Answer:
765 J
Step-by-step explanation:
We are given;
Mass of bucket = 30 kg
Mass of rope = 0.3 kg/m
height of building= 30 meter
Now,
work done lifting the bucket (sand and rope) to the building = work done in lifting the rope + work done in lifting the sand
Or W = W1 + W2
Work done in lifting the rope is given as,
W1 = Force x displacement
W1 = (30,0)∫(0.2x .dx)
Integrating, we have;
W1 = [0.2x²/2] at boundary of 30 and 0
W1 = 0.1(30²)
W1 = 90 J
work done in lifting the sand is given as;
W2 = (30,0)∫(F .dx)
F = mx + c
Where, c = 30 - 15 = 15
m = (30 - 15)/(30 - 0)
m = 15/30 = 0.5
So,
F = 0.5x + 15
Thus,
W2 = (30,0)∫(0.5x + 15 .dx)
Integrating, we have;
W2 = (0.5x²/2) + 15x at boundary of 30 and 0
So,
W2 = (0.5 × 30²)/2) + 15(30)
W2 = 225 + 450
W2 = 675 J
Therefore,
work done lifting the bucket (sand and rope) to the top of the building,
W = 90 + 675
W = 765 J
A type of bacterium triples in population every hour. Assuming you start with
90 bacteria, the formula that models the number of bacteria at the beginning
of hour nis:
a(n) = 90.3n-1
How many bacteria will there be at the beginning of hour 5?
Answer:
7290
Step-by-step explanation:
Put 5 in the formula and evaluate.
a(5) = 90·3^(5-1) = 90·81 = 7290
There will be 7290 bacteria at the beginning of hour 5.
Determine the least number of patties that will share equally among groups og 6, 9, 12
Answer:
72.
Step-by-step explanation:
Given a group of 6, 9 and 12.
We are to determine the least number of patties that will be shared equally among the groups.
This we do by determine the Least common multiple of the three numbers.
[tex]6=2 X 3\\9 = 3 X 3\\12 =2 X 2 X 2\\L.C.M.=2^3X3^2=72[/tex]
Therefore, the least number of patties that can be shares equally among groups of 6, 9 and 12 is 72.
The average retirement age for a certain country was reported to be 56.4 years according to an international group dedicated to promoting trade and economic growth. With the pension system operating with a deficit, a bill was introduced by the government during the summer to raise the minimum retirement age from 60 to 62. Suppose a survey of 40 retiring citizens is taken to investigate whether the new bill has raised the average age at which people actually retire. Assume the standard deviation of the retirement age is 55 years. Using α=0.10
Required:
Calculate the probability of a Type II error occurring if the actual population age is 57.5 years old.
Answer:
|Z| = |-0.126| = 0.126 < 1.645
Null hypothesis is accepted
The retiring citizens is taken to investigate whether the new bill has raised the average age at which people actually retire.
μ = 57.5
Step-by-step explanation:
Explanation:-
The average retirement age for a certain country was reported to be 56.4 years
The mean of the sample x⁻ = 56.4
The standard deviation of the Population 'σ'= 55 years
The mean of the population μ = 57.5
Null hypothesis: H₀:The retiring citizens is taken to investigate whether the new bill has raised the average age at which people actually retire.
μ = 57.5
Alternative Hypothesis : H₁: μ ≠57.5
Test statistic
[tex]Z = \frac{x^{-}-mean }{\frac{S.D}{\sqrt{n} } }[/tex]
critical value:
[tex]Z_{\frac{\alpha }{2} } = Z_{0.05} =1.645[/tex]
[tex]Z = \frac{56.4-57.5 }{\frac{55}{\sqrt{40} } } = -0.126[/tex]
|Z| = |-0.126| = 0.126 < 1.645
The null hypothesis is accepted
Conclusion:-
The retiring citizens is taken to investigate whether the new bill has raised the average age at which people actually retire.
μ = 57.5
How much will you save If you buy an Item listed at $575.50 at a 30 percent discount?
OA. $172.65
OB.
$176.25
O C. $185.63
Reset
Next
Answer:
Answer is A $172.25
Step-by-step explanation:
Step 1: Our output value is 575.50.
Step 2: We represent the unknown value with $x$.
Step 3: From step 1 above,$575.50=100\%$.
Step 4: Similarly, $x=30\%$.
Step 5: This results in a pair of simple equations
$575.50=100\%(1)$.
$x=30\%(2)$.
Step 6: By dividing equation 1 by equation 2 and noting that both the RHS (right hand side) of both
equations have the same unit (%); we have
$\frac{575.50}{x}=\frac{100\%}{30\%}$
Step 7: Again, the reciprocal of both sides gives
$\frac{x}{575.50}=\frac{30}{100}$
$\Rightarrow x=172.65$
Therefore, $30\%$ of $575.50$ is $172.65$
Answer:
The total that will be saved at a 30% discount is $172.65
Explanation:
Since, the marked up price of the item will be $575.50,
and the discount percentage is 30%,
Therefore, $ 172.65 will be saved.
if AB = 3, AD= 5, andDE= 6, what is the length of BC?
Answer:
D. 3.6
Step-by-step explanation:
=> Taking proportionality of the similar sides to find BC
[tex]\frac{AB}{AD}=\frac{BC}{DE}[/tex]
[tex]\frac{3}{5} = \frac{BC}{6}[/tex]
Multiplying 6 to both sides
[tex]BC = 0.6 * 6[/tex]
BC = 3.6
A researcher reports a 98% confidence interval for the proportion of Drosophila in a population with mutation Adh-F to be [0.34, 0.38). Therefore, there is an approximate probability of 0.98 that the proportion of Drosophola with this mutation is between 0.34 and 0.38.1. True 2. False
Answer:
[tex] 0.34 \leq p \leq 0.38[/tex]
For this case we can conclude that with 98% of confidence the true proportion of Drosophila in a population would be between 0.34 and 0.38.
But that doesn't means that we have 98% of PROBABILITY that the true proportion would be between 0.34 and 0.38, because we are constructing a confidence interval with sample data and we can't analyze this using probability.
Then the best answer is:
2. False
Step-by-step explanation:
For this case we have a confidence interval for the proportion of Drosophila in a population with mutation Adh-F to be given by:
[tex] 0.34 \leq p \leq 0.38[/tex]
For this case we can conclude that with 98% of confidence the true proportion of Drosophila in a population would be between 0.34 and 0.38.
But that doesn't means that we have 98% of PROBABILITY that the true proportion would be between 0.34 and 0.38, because we are constructing a confidence interval with sample data and we can't analyze this using probability.
Then the best answer is:
2. False
A fluid has density 860 kg/m3 and flows with velocity v = z i + y2 j + x2 k, where x, y, and z are measured in meters and the components of v in meters per second. Find the rate of flow outward through the cylinder x2 + y2 = 25, 0 ≤ z ≤ 1.
You can use the divergence theorem:
[tex]\vec v=z\,\vec\imath+y^2\,\vec\jmath+x^2\,\vec k[/tex]
has divergence
[tex]\mathrm{div}\vec v=\dfrac{\partial z}{\partial x}+\dfrac{\partial y^2}{\partial y}+\dfrac{\partial x^2}{\partial z}=2y[/tex]
Then the rate of flow out of the cylinder (call it R) is
[tex]\displaystyle\iint_{\partial R}\vec v\cdot\mathrm d\vec S=\iiint_R\mathrm{div}\vec v\,\mathrm dV[/tex]
(by divergence theorem)
[tex]=\displaystyle2\int_0^{2\pi}\int_0^5\int_0^1r^2\sin\theta\,\mathrm dz\,\mathrm dr\,\mathrm d\theta[/tex]
(after converting to cylindrical coordinates)
whose value is 0.
The amount of Jen’s monthly phone bill is normally
distributed with a mean of $55 and a standard deviation of $12. What percentage of her phone bills are between $19 and $91?
Answer:
[tex]P(19<X<91)=P(\frac{19-\mu}{\sigma}<\frac{X-\mu}{\sigma}<\frac{91-\mu}{\sigma})=P(\frac{19-55}{12}<Z<\frac{91-55}{12})=P(-3<z<2)[/tex]
And we can find this probability with this difference and using the normal standard distribution
[tex]P(-3<z<3)=P(z<3)-P(z<-3)=0.9987 -0.00135 =0.9974[/tex]
Step-by-step explanation:
Let X the random variable that represent the amount of Jen monthly phone of a population, and for this case we know the distribution for X is given by:
[tex]X \sim N(55,12)[/tex]
Where [tex]\mu=55[/tex] and [tex]\sigma=12[/tex]
We are interested on this probability
[tex]P(19<X<91)[/tex]
And we can use the z score formula given by:
[tex]z=\frac{x-\mu}{\sigma}[/tex]
Replacing the info we got:
[tex]P(19<X<91)=P(\frac{19-\mu}{\sigma}<\frac{X-\mu}{\sigma}<\frac{91-\mu}{\sigma})=P(\frac{19-55}{12}<Z<\frac{91-55}{12})=P(-3<z<2)[/tex]
And we can find this probability with this difference and using the normal standard distribution
[tex]P(-3<z<3)=P(z<3)-P(z<-3)=0.9987 -0.00135 =0.9974[/tex]
Indigo Depot is having a clearance sale of their summer items. A swimsuit that originally cost $120 before any discount is on sale for 15% off. If the swimsuit is then put on clearance for an additional 40% off the sale price, what is the final price? Round your answer to the nearest cent, if necessary.
Answer:
20
Step-by-step explanation:
Answer:
$61.20
Step-by-step explanation:
15% sale:
$120 - 15%= $120*0.85= $10240% sale:
$102 - 40%= $102*0.6= $61.20Which equation has two real solutions?
A. x2 = –100
B. 5x2 = 1
C. 6x2 + 17 = 11
D. 7(x2 + 6) = 42
Answer:
B. 5x² = 1Step-by-step explanation:
A. x² = –100
This equation has no solution because x² is always positive.
B. 5x² = 1
then x² = 1/5
then x = 1/(√5) or x = -1/(√5)
C. 6x² + 17 = 11
then 6x² = 11 - 17 = -6
then x² = -6/6 = -1
This equation has no solution because x² is always positive.
D. 7(x + 6) = 42
then x + 6 = 42/7 = 6
then x = 6 - 6 = 0
_____________________
:)
Point A on a coordinate grid is at (3, 4). What are the coordinates of R y=x (A)?
Answer:
A'(4, 3)
Step-by-step explanation:
When a point is reflected across the line y = x, the transformation is ...
(x, y) ⇒ (y, x)
A(3, 4) ⇒ A'(4, 3)
The reflected point is (4, 3).
laura quiere cúbrir con papel de china una puerta como la que se muestran el dibujo cuánto centímetros cuadrados es la que tendra que cubrir con papel de china
Answer:
Necesita cubrir 4800 cm^2.
Step-by-step explanation:
La pregunta está incompleta:
Laura quiere cubrir con papel de china una puerta como la que se muestra en el dibujo. Las medidas son 80 cm de largo y 60 cm de ancho.
Tenemos que calcular la superficie de la puerta, cuyas medidas son 80 cm de largo y 60 cm de ancho.
Para calcular el área simplemente multiplicamos las medidas de ambos lados:
[tex]A=80\,cm\cdot 60\,cm=4800\,cm^2[/tex]
A blueprint of a new house has a scale of 1inch 5 feet The length of the family room on the family room on the drawing is 4/4 inches. How long is the family room
Answer:87
Step-by-step explanation:
866
Please answer this correctly
Answer:
SA = 1,176 ft².
Step-by-step explanation:
To find the surface area of the triangular prism, we can solve for the rectangular base, both triangular faces, and lateral sides separately.
For the rectangular base: (Use formula l×w)
20 × 18 = 360 ft²
For the triangular faces: (Use formula 1/2(b·h)
1/2(18 × 12) = 108 ft²
Since there are two faces, we need to double the amount.
108 × 2 = 216 ft².
Finally, solve for the lateral sides:
20 × 15 = 300 ft².
There are two sides, so:
300 × 2 = 600 ft².
Add up all of these areas:
600 + 216 + 360 = 1,176 ft²
Lisa reads 46 pages and Sunday 15 pages on Monday and 19 pages on Tuesday which of the following is the closest to the mean number of the pages she read over the three dayperiod
Answer:
80
Step-by-step explanation:
46+15+19 which should give you a total answer of 80
plsss help meeeeeee I would really appreciate it I would be really happy if u help meeee
[tex]the \: answer \: is \: 22.4 \: cm \\ please \: see \: the \: attached \: picture \\ for \: full \: solution \\ hope \: it \: helps[/tex]
The length of AE is 22.4cm rounded to one decimal place.
A research firm regularly conducts customer satisfaction surveys for an amusement park. A survey of 100 randomly selected park visitors on a weekday in May concluded the average age of visitors to the park was 37 years. When the survey was repeated with 100 randomly selected park visitors on a Saturday in May the average age of visitors to the park was determined to be 17 years
a) What is the population of interest in this situation?
b) How many samples were described?
c) Is the average age of 37 years a parameter or a statistic?
d) Tell whether this information represents a quantitative or qualitative variable? - age of the visitor - whether the visitor has a season pass
e) What possible explanation is there for the large difference in age between the two samples?
Answer:
(a) The population of interest in this situation is the average age of visitors to the park in MAY during weekdays or weekends.
(b) Two samples are described in the above situation, that is;
A survey of 100 randomly selected park visitors on a weekday in May.A survey of 100 randomly selected park visitors on a Saturday in May.(c) The average age of 37 years is a statistic.
(d) The above information represents a quantitative variable.
(e) The possible explanation for the large difference in age between the two samples would be that during weekdays most of the teenagers or children below 20 years of age are not able to come to parks because of their schools, coachings or some studies related work.
Step-by-step explanation:
We are given that a research firm regularly conducts customer satisfaction surveys for an amusement park. A survey of 100 randomly selected park visitors on a weekday in May concluded the average age of visitors to the park was 37 years.
When the survey was repeated with 100 randomly selected park visitors on a Saturday in May the average age of visitors to the park was determined to be 17 years.
(a) The population of interest in this situation is the average age of visitors to the park in MAY during weekdays or weekends.
(b) Two samples are described in the above situation, that is;
A survey of 100 randomly selected park visitors on a weekday in May.A survey of 100 randomly selected park visitors on a Saturday in May.(c) The average age of 37 years is a statistic as it is the sample average age of visitors to the park on a weekday, i.e. [tex]\bar X_1[/tex] = 37 years.
(d) The above information represents a quantitative variable because in this we are concerned about the average age of visitors in the park which is a numeric value and we are not interested in any qualitative aspect.
(e) The possible explanation for the large difference in age between the two samples would be that during weekdays most of the teenagers or children below 20 years of age are not able to come to parks because of their schools, coachings or some studies related work.
But during weekends like Saturday, the schools or coaching institutions are generally closed due to which they are able to come to parks to play and because of this there are large number of children below 20 years of age who visit parks on weekends.
Mars, Inc. candy company claims the overall proportions for the colors of M&M’s are: .24 blue, .13 brown, .20 green, .16 orange, .13 red, and .14 yellow. You buy a large bag of M&M’s and observe the following counts: 105 blue, 72 brown, 89 green, 84 orange, 70 red, 80 yellow. At the 0.05 level of significance, is there evidence that the overall proportions for the colors are as stated above?
Answer:
There is insufficient statistical evidence to prove that the companies stated color distribution is not correct therefore, the overall proportions of the colors are correctly stated as above
Step-by-step explanation:
We have that
H₀: 0.24 blue, 0.13 brown, 0.20 green, 0.16 orange, 0.13 red and 0.14 yellow
The Data given are as follows;
Hₐ: The stated distribution of M&M is incorrect
Blue Brown Green Orange Red Yellow Total
Observed: 105 72 89 84 70 80 500
Expected: 120 65 100 80 65 70
We have;
[tex]\chi ^{2}=\dfrac{\left (105-120 \right )^{2}}{120}+ \dfrac{\left (72-65\right )^{2}}{65} + \dfrac{\left (89-100\right )^{2}}{100} + \dfrac{\left (84-80\right )^{2}}{80} + \dfrac{\left (70-65\right )^{2}}{65} + \dfrac{\left (80-70\right )^{2}}{70} = 5.85[/tex]
At 6 - 1 = 5 degrees of freedom we find the p-value from the chi squared table as follows
P(0.05) at 5% degrees of freedom =11.070 hence our P-value is larger than 0.05 and we fail to reject the null hypothesis, hence there is insufficient statistical evidence to prove that the companies stated color distribution is not correct.
Solve 5x - c = k for x.
Answer:
Step-by-step explanation:
5x - c = k
Add c to each side
5x - c+c = k+c
5x = (k+c)
Divide each side by 5
5x/5 = (k+c)/5
x = (k+c)/5
Answer:
x=(k+c)/5
Step-by-step explanation:
5x-c=k (Original Equation)
5x-c+c=k+c (Addition Property of Equality)
5x=k+c (Simplify)
x=(k+c)/5 (Division Property of Equality)
graph the function f(x)=(x+2)(x-4). Which describes all of the values for which the graph is negative and decreasing?
Answer:
[tex]x\in(-2,1)[/tex]
Step-by-step explanation:
We are given that a function
[tex]f(x)=(x+2)(x-4)[/tex]
[tex]f(x)=x^2-2x-8[/tex]
Differentiate w.r.t x
[tex]f'(x)=2x-2[/tex]
[tex]f'(x)=0[/tex]
[tex]2x-2=0[/tex]
[tex]2x=2\implies x=\frac{2}{2}=1[/tex]
Therefore, intervals
[tex](-\infty,1),(1,\infty)[/tex]
Interval :[tex](-\infty,1)[/tex]
x=0
[tex]f'(0)=-2<0[/tex]
Decreasing function.
Interval:[tex](1,\infty)[/tex]
Substitute x=2
[tex]f'(2)=2(2)-2=2>0[/tex]
Function increasing.
From given graph we can see that function is negative for the values of x
-2<x<4
Hence, the graph is negative and decreasing for the values of x
[tex]x\in(-2,1)[/tex]
Answer:the answer is c/ all real values of x where 1<x<4
Step-by-step explanation:
edge 2020
A circle is defined by the equation given below.
x^2+y^2-x-2y-11/4=0
What are the coordinates for the center of the circle and the length of the radius?
Answer:
(1/2, 1)
2
Step-by-step explanation:
x² + y² − x − 2y − 11/4 = 0
x² − x + y² − 2y = 11/4
Complete the squares.
x² − x + 1/4 + y² − 2y + 1 = 11/4 + 1/4 + 1
(x − 1/2)² + (y − 1)² = 4
The center of the circle is (1/2, 1) and the radius of the circle is 2.
Answer:
Option A
Step-by-step explanation:
[tex](\frac{1}2} ,1)[/tex], 2 units
How much money does the average professional hockey fan spend on food at a single hockey game? That question was posed to 10 randomly selected hockey fans. The sampled results show that sample mean and standard deviation were $ 18.00 and $ 2.75, respectively. Use this information to create a 90% confidence interval for the mean. Express the answer in the form x overbar plus or minus t Subscript alpha divided by 2 Baseline (s divided by StartRoot n EndRoot ).
Answer:
Now we have everything in order to replace into formula (1):
[tex]18-2.262\frac{2.75}{\sqrt{10}}=16.03[/tex]
[tex]18+2.262\frac{2.75}{\sqrt{10}}=19.97[/tex]
Step-by-step explanation:
Information given
[tex]\bar X=18[/tex] represent the sample mean
[tex]\mu[/tex] population mean (variable of interest)
s=2.75 represent the sample standard deviation
n=10 represent the sample size
Confidence interval
The confidence interval for the mean is given by the following formula:
[tex]\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}[/tex] (1)
The degrees of freedom are given by:
[tex]df=n-1=10-1=9[/tex]
The Confidence is 0.90 or 90%, the significance is [tex]\alpha=0.1[/tex] and [tex]\alpha/2 =0.05[/tex], and the critical vaue would be [tex]t_{\alpha/2}=2.262[/tex]
Now we have everything in order to replace into formula (1):
[tex]18-2.262\frac{2.75}{\sqrt{10}}=16.03[/tex]
[tex]18+2.262\frac{2.75}{\sqrt{10}}=19.97[/tex]
Select the correct answer from each drop-down menu. A quadrilateral has vertices A(11, -7), B(9, -4), C(11, -1), and D(13, -4). Quadrilateral ABCD is a . If the vertex C(11, -1) were shifted to the point C′(11, 1), quadrilateral ABC′D would be a .
Answer:
Quadrilateral ABCD is a Quadrilateral with four equal sides so either a rhombus or square
But
Quadrilateral ABC'D is a quadrilateral with two adjacent sides equal so it's a kite shape
Step-by-step explanation:
(11, -7), B(9, -4), C(11, -1), and D(13, -4).
Let's take out the values of x and y coordinate with the way they are arranged
X = 11,9,11,13
Y = -7,-4,-1,-4
So we observe that distance of the coordinates on either x is 2 units and y is 3 units.
But when the the value was changed to
C′(11, 1), (11, -7), B(9, -4), C′(11, 1), and D(13, -4).
There was difference of 2 unit and 4 unit making the new shape a kite.
The diagram attached explain better
Answer:
1. rhombus with non-perpendicular adjacent sides
2. kite
Step-by-step explanation:
i just got it right on edmentum.
Please mark as brainliest.
State if each scenario involves a permutation or a combination. Then find the number of possibilities.
The batting order for seven players on a 8 person team.
a)Permutations: 120.960
b)Combinations: 20,160
c)Permutations: 40320
d)Combinations: 8
Answer:
c) Permutations: 40320
Step-by-step explanation:
We have that permutations are groupings in which the order of the objects matters. Combinations are groupings where content matters but order does not.
In this case, then the batting order, therefore the order does matter, therefore, it would be a permutation, where n = 8 and r = 7
nPr = n! / (n-r)!
Replacing:
8P7 = 8! / (8-7)! = 40320
Which means that the answer is c) Permutations: 40320
Three potential employees took an aptitude test. Each person took a different version of the test. The scores are reported below. Alissa got a score of 68.568.5; this version has a mean of 60.460.4 and a standard deviation of 99. Morgan got a score of 252.5252.5; this version has a mean of 227227 and a standard deviation of 1717. Norma got a score of 7.967.96; this version has a mean of 6.76.7 and a standard deviation of 0.70.7. If the company has only one position to fill and prefers to fill it with the applicant who performed best on the aptitude test, which of the applicants should be offered the job?
Answer:
Due to the higher Z-score, Norma should be offered the job
Step-by-step explanation:
Z-score:
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question:
Whoever has the higher z-score should be offered the job.
Alissa:
[tex]X = 68.5, \mu = 60.4, \sigma = 9[/tex]
So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{68.5 - 60.4}{9}[/tex]
[tex]Z = 0.9[/tex]
Morgan:
[tex]X = 252.5, \mu = 227, \sigma = 17[/tex]
So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{252.5 - 227}{17}[/tex]
[tex]Z = 1.5[/tex]
Norma:
[tex]X = 7.96, \mu = 6.7, \sigma = 0.7[tex]
So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{7.96 - 6.7}{0.7}[/tex]
[tex]Z = 1.8[/tex]
Due to the higher Z-score, Norma should be offered the job
Do consumers spend more on a trip to Target or Walmart? Suppose researchers interested in this question collected a systematic sample for 84 Target customers and 80 Walmart customers by asking customers for their purchase amount as they left the store. Using the given summary statistics, researchers calculated a 95% confidence interval for the mean difference between Target and Walmart purchase amounts. The interval was ($negative 15.05,$negative 2.95). Explain in context what this interval means.
Answer:
Step-by-step explanation:
Confidence interval for the difference between two population means is written in the form,
difference in sample means ± margin of error
The difference in sample means is the point estimate for the difference in population means. In the given scenario, the point estimate is the difference in mean amount spent by the sampled customers on a trip to Target or Walmart.
Since the interval was (- $15.05,$2.95), it means that the lower limit is - $15.05 and the upper limit us $2.95.
Therefore, the 95% confidence interval is providing a range that we are 95% confident that the true difference in mean amount spent by Target customers and Walmart customers falls between - $15.05 and $2.95
There are 11 apples in a basket. 9 of these apples are green. The rest of them are red. What is the ratio of red apples to all apples in the basket? What is the ratio of red apples to green apples?
Answer:
Red apples to all apples =2/11
Red apples to green apples =2/9
Step-by-step explanation:
There are 11 total apples 9 of them are green and the rest are red so there are 11-9=2 red apples
The ratio of red apples to all apples = number of red apples ÷ total apples number = 2÷11
The ratio of red apples to green apples = number of red apples ÷ number of green apples = 2÷9
Answer:
Red apples to all apples =2/11
Red apples to green apples =2/9
Step-by-step explanation:
There are 11 total apples 9 of them are green and the rest are red so there are 11-9=2 red apples
The ratio of red apples to all apples = number of red apples ÷ total apples number = 2÷11
The ratio of red apples to green apples = number of red apples ÷ number of green apples = 2÷9
Step-by-step explanation:
Perhaps the most popular fighter since the turn of the decade, Ronda Rousey is famous for defeating her opponents quickly. The five number summary for the times of her first 12 UFC (Ultimate Fighting Championship) fights, in seconds, is .(a) Only three of her fights have lasted more than a minute, at 289, 267, and 66 seconds, respectively. Use the IQR method to see which, if any, of these values are high outliers. (b) Are there any low outliers in these data, according to the IQR method? (c) Draw the boxplot for Ronda Rousey's fight times. (d) Based on the boxplot or five number summary, would we expect Ronda's mean fight time to be greater than or less than her median?
Answer:
Step-by-step explanation:
Hello!
The variable of interest is "the time a fight lasts" measured in seconds
The five number summary for her first 12 UFC fights are:
Minimum: Min= 14
First Quartile: Q₁= 25
Second Quartile/Median: Me= 44
Third Quartile: Q₃= 64
Maximum: Max= 289
a)
Three of her fights lasted more than one minute: 289, 267, 66. Out of these three fights, you have to determine if they are outliers using the IQR method.
The IQR is the distance between the third quartile and the first quartile
IQR= Q₃ - Q₁= 64 - 25= 39
Remember, an outlier is an observation that is significantly distant from the rest of the data set. They usually represent experimental errors (such as a measurement) or atypical observations. Some statistical measurements, such as the sample mean, are severely affected by this type of values and their presence tends to cause misleading results on a statistical analysis.
Considering the 1st quartile (Q₁), the 3rd quartile (Q₃) and the interquartile range IQR, any value X is considered an outlier if:
X < Q₁ - 1.5 IQR
X > Q₃ + 1.5 IQR
Or extreme outliers if:
X < Q₁ - 3 IQR
X > Q₃ + 3 IQR
The limits that define if a value is an outlier or not are:
X < 25 - 1.5*39 = -33.5
X > 64 + 1.5*39= 122.5
And for extreme outliers:
X < 25 - 3*39 = -92
X > 64 + 3*39= 181
So fights that lasted less than -33.5 or more than 122.5 seconds are to be considered outliers, and those who lasted less than -92 or more than 181 seconds are extreme outliers.
Out of the three fights, the ones that lasted 289 and 267 seconds can be considered extreme values.
b) The minimum observed value for this data set is 14 seconds, values are considered to be outliers if they are less to -33.5, so there is no low outliers on the sample.
As you can see, both values that allow you to determine if the observation is an outlier or not are negative, since the variable is "the time a fight lasts" it is impossible for it to have negative values. The lowest value of time a fight can last is "zero seconds". Although mathematically correct, these values make no sense.
c)
See attachment.
d)
The average or mean is a measurement of central tendency that shows you the value around which most of the distribution will be. It is very affected by the presence of outliers, especially extreme ones. Outliers make the mean "move" towards them, this means, that if there are small outliers, then the mean will move to the lower side of the distribution. But if the outliers are big, then the mean will move to the higher side of the distribution.
For example, let's say 5 of the fight times were:
10, 37, 49, 51, 68
For these values the mean would be:
X[bar]₀= ∑X/n= (10+37+49+51+68)/5= 215/5= 43
Now let's change one of these values for an extreme one:
Small value:
0, 37, 49, 51, 68
X[bar]₁= ∑X/n= (0+37+49+51+68)/5= 205/5= 41
⇒ As you can see, one change for a smaller value reduces the mean value X[bar]₁ < X[bar]₀
Big value:
10, 37, 49, 51, 268
X[bar]₂= ∑X/n= (10+37+49+51+268)/5= 415/5= 83
⇒ In this case, changing one of the 5 values to a bigger one moved the mean to the right: X[bar]₀ < X[bar]₂
So for the given distribution, since there are at least two high outliers, you'd expect the mean to be greater than the median.
I hope this helps!
Determine the center and radius of the circle described by the question.
(X+2)
The question is incomplete, I will however explain, with an illustration, how to determine the center and radius of a circle.
Step-by-step explanation:
The standard equation of a circle is given as:
(x - a)² + (y - b)² = r² ........................(1)
Where (a, b) is the center of the circle, and r is the radius.
An expression can be given for us to find the center and the radius of the circle.
Suppose we were given the expression:
x² + y² - 10x + 4y - 7 = 0.....................(2)
To find the center and the radius, it is left for us to rewrite (2) in the form of (1).
Rearranging (2), we have
(x² - 10x) + (y² + 4y) = 7
Completing the squares of each bracket
(x² - 10x + 25 - 25) + (y² + 4y + 4 - 4) = 7
(x² - 10x + 25) + (y² + 4y + 4) - 25 - 4 = 7
(x² - 10x + 25) + (y² + 4y + 4) - 29 = 7
(x - 5)² + (y + 2)² = 7 + 29
(x - 5)² + (y + 2)² = 36
Or
(x - 5)² + (y + 2)² = 6² .....................(3)
Comparing (3) with one, we see that
a = 5, b = -2, and r = 6
Therefore it is a circle centered at (5, -2) with a 6 unit radius.
Find the nth term of this number sequence 7,10,13,16
Answer:
aₙ = 7 +3(n -1)
Step-by-step explanation:
The numbers in the given sequence have a common difference, so this is an arithmetic sequence. The formula for the n-th term applies.
aₙ = a₁ +d(n -1)
ApplicationThe first term is 7. The common difference is 10-7 = 3. Using the above formula for the n-th term, we find it to be ...
aₙ = 7 +3(n -1)
__
Additional comment
This can be simplified to ...
aₙ = 3n +4