Answer:
x = -2.47, 0.47
Step-by-step explanation:
Easiest and quickest way to do this is to graph the quadratic and analyze for x-intercepts.
Alternatively, we have to use the Quadratic Formula because we cannot factor the expression.
heres a list of numbers 3 6 9 7 4 6 7 0 7 Find median,mean,range and mode
median=order them and find the middle=6
mean=add them all up and divide by the amount of numbers=(3+6+9+7+4+6+7+0 +7)/9=5.4
range= the difference between the smallest and largest number=9-3=6
mode= the one that appears the most= 7
The median, mean, range and mode will be 6, 5.4, 9 and 7.
The median is the number in the middle when arranged in an ascending order. The numbers will be:
0, 3, 4, 6, 6, 7, 7, 7, 9.
The median is 6.
The range is the difference between the highest and lowest number which is: = 9 - 0 = 9
The mode is the number that appears most which is 7.
The mean will be the average which will be:
= (0 + 3 + 4 + 6 + 6 + 7 + 7 + 7 + 9) / 9.
= 49/9
= 5.4
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write the equation of a circle with the center (6,4) that passes through the coordinate (2,1) in your final answer include all of your calculations
Step-by-step explanation:
define define equation we need the value of the radius and
What is 1 standard deviation on a
normal curve?
A. Another name for the mean.
B. Another name for the inflection point.
C. The distance from the mean to the bottom of the
curve.
D. The distance from the mean to an inflection point.
Answer:
D. The distance from the mean to an inflection point
Step-by-step explanation:
We rarely encounter the actual formula for the normal PDF. It is ...
[tex]p(x)=\dfrac{1}{\sqrt{2\pi}}e^{-\dfrac{x^2}{2}}[/tex]
In fact, the inflection points are at x = ±1, where the curve changes from being concave downward to concave upward.
So, one standard deviation is the distance from the mean to an inflection point.
By what percent will the fraction increase if its numerator is increased by 60% and denominator is decreased by 20% ?
Answer:
100%
Step-by-step explanation:
Start with x.
x = x/1
Increase the numerator by 60% to 1.6x.
Decrease the numerator by 20% to 0.8.
The new fraction is
1.6x/0.8
Do the division.
1.6x/0.8 = 2x
The fraction increased from x to 2x. It became double of what it was. From x to 2x, the increase is x. Since x was the original number x is 100%.
The increase is 100%.
Answer:
33%
Step-by-step explanation:
let fraction be x/y
numerator increased by 60%
=x+60%ofx
=8x
denominator increased by 20%
=y+20%of y
so the increased fraction is 4x/3y
let the fraction is increased by a%
then
x/y +a%of (x/y)=4x/3y
or, a%of(x/y)=x/3y
[tex]a\% = \frac{x}{3y} \times \frac{y}{x} [/tex]
therefore a=33
anda%=33%
I'm having a hard time with this. A new housing development extends 4 miles in one direction, makes a right turn, and then con- tinues for 3 miles. A new road runs between the beginning and ending points of the development. What is the perimeter of the triangle formed by the homes and the road? What is the area of the housing development?
Answer:
perimeter = 12 miles
area = 6 square miles
Step-by-step explanation:
Since it makes a right triangle, use the Pythagorean Formula.
3^2+4^2=c^2
9+16=c^2
25=c^2
5=c, so the hypotenuse of the right triangle is 5.
Perimeter = 3+4+5 = 12 miles
area = 1/2bh (1/2 base times height)
=1/2x3x4
=6
Area = 6 square miles
can someone help me with 8÷2 2/9 −2 11/15
Answer:
7/3 or 13/15
Step-by-step explanation:
So you told me that it will be
8/(20/9) -2 11/15 I put parenthesis to make it easier to understand for me
so you must know that a/(b/c)=ac/b si
72/20 -2 11/15 so we work with -2 11/15 which is equal to -30/15 + 11/15 and that will be -19/15 so we have
72/20 - 19/15 we simplify
18/5 - 19/15 so we multiply and divide by 3 in 18/5
54/15 - 19/15 and we add up
35/15 which is equal to
7/3
If this is wrong so we work with -2 11/15 which is equal to -30/15 + 11/15 well it should be so we work with -2 11/15 which is equal to -30/15 - 11/15 and that equals -41/15 and we get
54/15-41/15
13/15
An automobile manufacturer has given its car a 46.7 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the actual MPG for this car since it is believed that the car has an incorrect manufacturer's MPG rating. After testing 150 cars, they found a mean MPG of 46.5. Assume the population standard deviation is known to be 1.1. A level of significance of 0.05 will be used. Find the value of the test statistic. Round your answer to two decimal places.
Answer:
[tex]z=\frac{46.5-46.7}{\frac{1.1}{\sqrt{150}}}=-2.23[/tex]
The p value would be given by:
[tex]p_v =2*P(z<-2.23)=0.0257[/tex]
For this case since th p value is lower than the significance level of0.05 we have enough evidence to reject the null hypothesis and we can conclude that the true mean for this case is significantly different from 46.7 MPG
Step-by-step explanation:
Information given
[tex]\bar X=46.5[/tex] represent the mean
[tex]\sigma=1.1[/tex] represent the population standard deviation
[tex]n=150[/tex] sample size
[tex]\mu_o =46.7[/tex] represent the value to verify
[tex]\alpha=0.05[/tex] represent the significance level for the hypothesis test.
z would represent the statistic
[tex]p_v[/tex] represent the p value
Hypothesis to test
We want to test if the true mean for this case is 46.7, the system of hypothesis would be:
Null hypothesis:[tex]\mu = 46.7[/tex]
Alternative hypothesis:[tex]\mu \neq 46.7[/tex]
Since we know the population deviation the statistic is given by:
[tex]z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}[/tex] (1)
Replacing we got:
[tex]z=\frac{46.5-46.7}{\frac{1.1}{\sqrt{150}}}=-2.23[/tex]
The p value would be given by:
[tex]p_v =2*P(z<-2.23)=0.0257[/tex]
For this case since th p value is lower than the significance level of0.05 we have enough evidence to reject the null hypothesis and we can conclude that the true mean for this case is significantly different from 46.7 MPG
Claim: Most adults would erase all of their personal information online if they could. A software firm survey of 421 randomly selected adults showed that 65% of them would erase all of their personal information online if they could. Find the value of the test statistic.
Answer:
The statistic would be given by:
[tex]z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}[/tex] (1)
And replacing we got:
[tex]z=\frac{0.65 -0.5}{\sqrt{\frac{0.5(1-0.5)}{421}}}=6.16[/tex]
Step-by-step explanation:
Information given
n=421 represent the random sample taken
[tex]\hat p=0.65[/tex] estimated proportion of adults that would erase all of their personal information online if they could
[tex]p_o=0.5[/tex] is the value that we want to test
z would represent the statistic
Hypothesis to test
We want to check if Most adults would erase all of their personal information online if they could, then the system of hypothesis are :
Null hypothesis:[tex]p\leq 0.5[/tex]
Alternative hypothesis:[tex]p > 0.5[/tex]
The statistic would be given by:
[tex]z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}[/tex] (1)
And replacing we got:
[tex]z=\frac{0.65 -0.5}{\sqrt{\frac{0.5(1-0.5)}{421}}}=6.16[/tex]
From the information given, it is found that the value of the test statistic is z = 6.16.
At the null hypothesis, we test if it is not most adults that would erase all of their personal information online if they could, that is, the proportion is of at most 50%, hence:
[tex]H_0: p = 0.5[/tex]
At the alternative hypothesis, we test if most adults would, that is, if the proportion is greater than 50%.
[tex]H_1: p > 0.5[/tex]
The test statistic is given by:
[tex]z = \frac{\overline{p} - p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]
In which:
[tex]\overline{p}[/tex] is the sample proportion. p is the proportion tested at the null hypothesis. n is the sample size.In this problem, the parameters are: [tex]p = 0.5, n = 421, \overline{p} = 0.65[/tex].
Hence, the value of the test statistic is:
[tex]z = \frac{\overline{p} - p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]
[tex]z = \frac{0.65 - 0.5}{\sqrt{\frac{0.5(0.5)}{421}}}[/tex]
[tex]z = 6.16[/tex]
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Any polygon can be the base of a prism. A. True B. False
Answer:
true
Step-by-step explanation:
A prism is a solid with parallelogram sides (usually rectangles) and a polygon for the 2 bases. Any polygon can be the base.
Answer:
Hello!
__________________
Your answer would be (A) True.
Step-by-step explanation: Hope this helped you!
Any polygon can be the base of a prism so the answer is true.
What is the value of x in the equation 0.7 x - 1.4 = -3.5
Answer:
x=12.5
Step-by-step explanation:
0.7x times (-1.4)=-3.5
-0.28x=-3.5 (divide both sides)
Ans:12.5
Which set of numbers could represent the lengths of the sides of a triangle? A. {3,4,8} B. {8,11,19} C. {11,5,5} D. {19,16,20}
Answer:
19, 16, 20
Step-by-step explanation:
The Triangle Inequality Theorem states that the sum of any 2 sides of a triangle must be greater than the measure of the third side.
Aka the highest number - the next highest number = lowest possible number.
3+4 is not greater than 8.
8 + 11 is not greater than 19.
5 + 5 is not greater than 11.
16+19 is greater than 20.
19+20 is greater than 16.
16+ 20 is greater than 19.
the set of numbers that could represent the lengths of the sides of a triangle is D. {19, 16, 20}.
To determine if a set of numbers can represent the lengths of the sides of a triangle, we need to apply the triangle inequality theorem. According to the theorem, for a triangle with side lengths a, b, and c:
a + b > c
a + c > b
b + c > a
Let's evaluate each set of numbers:
A. {3, 4, 8}
3 + 4 > 8 (7 > 8) - Not true
4 + 8 > 3 (12 > 3) - True
3 + 8 > 4 (11 > 4) - True
Since the first inequality is not true, set A cannot represent the lengths of the sides of a triangle.
B. {8, 11, 19}
8 + 11 > 19 (19 > 19) - Not true
8 + 19 > 11 (27 > 11) - True
11 + 19 > 8 (30 > 8) - True
Since the first inequality is not true, set B cannot represent the lengths of the sides of a triangle.
C. {11, 5, 5}
11 + 5 > 5 (16 > 5) - True
11 + 5 > 5 (16 > 5) - True
5 + 5 > 11 (10 > 11) - Not true
Since the third inequality is not true, set C cannot represent the lengths of the sides of a triangle.
D. {19, 16, 20}
19 + 16 > 20 (35 > 20) - True
19 + 20 > 16 (39 > 16) - True
16 + 20 > 19 (36 > 19) - True
All three inequalities are true for set D, so it can represent the lengths of the sides of a triangle.
Therefore, the set of numbers that could represent the lengths of the sides of a triangle is D. {19, 16, 20}.
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ten percent of 140,000 = ?
Answer:
14000
Step-by-step explanation:
Of means multiply
10% * 140000
Change to decimal form
.10 * 140000
14000
Answer:
[tex]14000[/tex]
Step-by-step explanation:
[tex]10\% \times 140000[/tex]
[tex]\mathrm{Apply} \: a\% = \frac{a}{100}[/tex]
[tex]\frac{10}{100} \times 140000[/tex]
[tex]\mathrm{Apply} \: \frac{a}{100} \times b = \frac{ab}{100}[/tex]
[tex]\frac{1400000}{100}[/tex]
[tex]\mathrm{Simplify.}[/tex]
[tex]\frac{14000}{1} =14000[/tex]
ratio 300 ml to 6 l
Answer:
20
Step-by-step explanation:
fist you convert 6l to ml=6×1000
then,300/300:6000/300
gives you 1:20
Profit Function for Producing Thermometers The Mexican subsidiary of ThermoMaster manufactures an indoor-outdoor thermometer. Management estimates that the profit (in dollars) realizable by the company for the manufacture and sale of x units of thermometers each week is represented by the function below, where x ≥ 0. Find the interval where the profit function P is increasing and the interval where P is decreasing. (Enter your answer using interval notation.) P(x) = −0.004x2 + 6x − 5,000 Increasing: Decreasing:
Answer:
Increasing: [tex](0, 750)[/tex]
Decreasing: [tex](750, \infty)[/tex]
Step-by-step explanation:
Critical points:
The critical points of a function f(x) are the values of x for which:
[tex]f'(x) = 0[/tex]
For any value of x, if f'(x) > 0, the function is increasing. Otherwise, if f'(x) < 0, the function is decreasing.
The critical points help us find these intervals.
In this question:
[tex]P(x) = -0.004x^{2} + 6x - 5000[/tex]
So
[tex]P'(x) = -0.008x + 6[/tex]
Critical point:
[tex]P'(x) = 0[/tex]
[tex]-0.008x + 6 = 0[/tex]
[tex]0.008x = 6[/tex]
[tex]x = \frac{6}{0.008}[/tex]
[tex]x = 750[/tex]
We have two intervals:
(0, 750) and [tex](750, \infty)[/tex]
(0, 750)
Will find P'(x) when x = 1
[tex]P'(x) = -0.008x + 6 = -0.008*1 + 6 = 5.992[/tex]
Positive, so increasing.
Interval [tex](750, \infty)[/tex]
Will find P'(x) when x = 800
[tex]P'(x) = -0.008x + 6 = -0.008*800 + 6 = -0.4[/tex]
Negative, then decreasing.
Answer:
Increasing: [tex](0, 750)[/tex]
Decreasing: [tex](750, \infty)[/tex]
f(x)={x+1]^2 Determine for each x-value whether it is in the domain of f or not. (-2 y/n} { -1 y/n} {9 y/n}
Answer:
all are "yes"
Step-by-step explanation:
A polynomial is defined for all values of x. None are excluded. Every value listed is in the domain of f(x) = (x +1)².
Answer:
Step-by-step explanation:
Students in a zoology class took a final exam. They took equivalent forms of the exam at monthly intervals thereafter. After t months, the average score S(t), as a percentage, was found to be given by the following equation, whereStudents in a zoology class took a final exam. They took equivalent forms of the exam at monthly intervals thereafter. After t months, the average score S(t), as a percentage, was found to be given by the following equation, where t>=0.
Required:
a. What was the average score when they initially took the test, t=0?
b. What was the average score after 4 months?
c. What was the average score after 24 months?
d. What percentage of their original answers did the students retain after 2 years?
e. The maximum of the function is_____%.
Answer:
a. 73; b. 48.9; c. 2; d. 33.8; e. 73
Step-by-step explanation:
Assume the function was
S(t)= 73 - 15 ln(t + 1), t ≥ 0
a. Average score at t = 0
S(0) = 73 - 15 ln(0 + 1) = 73 - 15 ln(1) = 73 - 15(0) =73 - 0 = 73
b. Average score at t = 4
S(4) = 73 - 15 ln(4 + 1) = 73 - 15 ln(5) = 73 - 15(1.61) =73 - 24.14 = 48.9
c. Average score at t =24
S(24) = 73 - 15 ln(24 + 1) = 73 - 15 ln(25) = 73 - 15(3.22) =73 - 48.28 = 24.7
d. Percent of answers retained
At t = 0. the students retained 73 % of the answers.
At t = 24, they retained 24.7 % of the answers.
[tex]\text{Percent retention} = \dfrac{\text{24.7}}{\text{73}} \times 100 \, \% = \text{33.8 \%}\\\\\text{The students retained $\large \boxed{\mathbf{33.8 \, \%}}$ of their original knowledge after two years.}[/tex]
e. Maximum of the function
The maximum of the function is at t= 0.
Max = 73 %
The graph below shows your knowledge decay curve. Knowledge decays rapidly at first but slows as time goes on.
please please please please help i need to pass please
Answer:
D
Step-by-step explanation:
Solution:-
The standard sinusoidal waveform defined over the domain [ 0 , 2π ] is given as:
f ( x ) = sin ( w*x ± k ) ± b
Where,
w: The frequency of the cycle
k: The phase difference
b: The vertical shift of center line from origin
We are given that the function completes 2 cycles over the domain of [ 0 , 2π ]. The number of cycles of a sinusoidal wave is given by the frequency parameter ( w ).
We will plug in w = 2. No information is given regarding the phase difference ( k ) and the position of waveform from the origin. So we can set these parameters to zero. k = b = 0.
The resulting sinusoidal waveform can be expressed as:
f ( x ) = sin ( 2x ) ... Answer
Find the length of KU
Answer:
KU = 8
Step-by-step explanation:
From the diagram
KU + UN = KN , that is
KU + 40 = 48 ( subtract 40 from both sides )
KU = 8
Answer:
KU = 8
Step-by-step explanation:
UN = 40
KN = 48
KU + UN = 48
KU + 40 = 48 {Subtract 40 from both sides}
KU = 48 -40
KU = 8
Find the upper and lower sums for the region bounded by the graph of the function and the x-axis on the given interval. Leave your answer in terms of n, the number of subintervals. Function Interval f(x) = 7 − 2x [1, 2]
Answer:
-2n
Step-by-step explanation:
f(x)=7-2x {1,2}
f(1)=7-2(1)=5
f(2)=7-2(2)=3
Slope (m)=3/5
{7-2(1)}-{7-2(2)}=3-5=-2
In terms of n=-2n
The upper and lower sums for the region bounded by the graph of the function and the x-axis on the given interval is [5, 3]
Given the function of the graph bounded by the inteval [1, 2] expressed as
f(x) = 7 - 2x
The upper limit of the function is the point where the domain of the function x is 2. Substitute x = 2 into the function, we will have:
f(2) = 7 - 2(2)
f(2) = 7 - 4
f(2) = 3
For the lower limit, the domain of the function is at x = 2:
f(1) = 7 - 2(1)
f(1) = 7 - 2
f(1) = 5
Hence the upper and lower sums for the region bounded by the graph of the function and the x-axis on the given interval is [5, 3].
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Please help don't understand this. The function g is a transformation of f. If g has a y-intercept at -1, which of the following functions could represent g?
Explanation:
The graph shows that f(x) has the y intercept at -5. This is where the red line crosses the vertical y axis. More specifically, the y intercept is located at the point (0,-5)
We're told that g(x) has a y intercept at -1. So we must move f(x) 4 units up to go from y = -5 to y = -1. This is because -5+4 = -1.
Do this for every point on f(x) and you'll end up with g(x) = f(x)+4. Recall that y = f(x). So saying f(x)+4 is the same as y+4 to indicate "shift up 4 units".
f(x) and g(x) have the same slope, but different y intercepts. So they are parallel lines that never cross.
You are ordering softballs for two softball leagues. The Elementary League uses a
larger softball priced at $2.75 each. The Middle School league uses a smaller softball
prices at $3.25 each. You order a total of 80 softballs for $245. What equations
would you use to find out how many of each size of softball you can order. Let L =
the larger softball and let S = the smaller softball.
Answer:L=30 S=50
Step-by-step explanation:
3.25 x 50 = 162.5
245 - 162.5 = 82.5
82.5 divided by 30 equals 2.75.
What is 3 1/2 times 4?
Answer:
14
Step-by-step explanation:
3 1/2 × 4
Convert 3 1/2 to an improper fraction.
7/2 × 4
7/2 × 4/1
Multiply.
(7× 4) / (2 × 1)
28 / 2
= 14
Answer: 14
Step-by-step explanation: To multiply a mixed number times a whole number, first write each of them as an improper fraction.
So we can rewrite 3 and 1/2 as the improper fraction 7/2
and we can write 4 as the improper fraction 4/1.
If you've forgotten how to write a mixed number as an improper fraction, feel free to ask me below and I will review this with you.
So now we have 7/2 × 4/1.
When we're multiplying fractions, we want to
cross-cancel first whenever possible.
So here, notice that we can cross-cancel 2 and 4 to 1 and 2.
So we have 7/1 × 2/1.
Now we just multiply across the numerators and multiply across the denominators and we have our answer, 14/1 or just 14.
Find the area of a circle with a diameter of 8yards. Use 3.14. The area of the circle is approximate
Answer:
50.24 yd²
Step-by-step explanation:
pi r² = (3.14)(4)² = 50.24
James plays at the neighborhood basketball court which is enclosed by a circular fence. The circle created by fence has a radius of 50 feet. What is the APPROXIMATE area of the space enclosed by the fence? Use 3.14 for π. 1,962.5 sq ft 7,850 sq ft 157.5 sq ft 314 sq ft
Answer:
7850 feet.sq
Step-by-step explanation:
the area of a cercle is:
A = r²*π where r is the radius
A= 50²*3.14 = 7850 ft²
Perform a glide reflection over the x-axis and 6 units to the right. Write the new coordinates. Then complete the translation. Thanks.
Answer:
After reflection, the coordinates would be A(-6,-8) B(-2,-6) C(-4,-2) and D(-8,-4). After translation, the coordinates would be A(0,-8) B(4,-6) C(2,-2) and D(-2,-4).
Step-by-step explanation:
If the figure ABCD consists of 4 points and we want to reflect this across the x-axis, then the y coordinate values of A, B, C and D will be negated. So,
(-6,8) becomes (-6,-8)
(-2,6) becomes (-2,-6)
(-4,2) becomes (-4,-2)
and (-8,4) becomes (-8,-4).
Now that we know what the reflection is, we translate it 6 units to the right. Therefore, the x value of each coordinate is increased by 6.
(-6,-8) becomes (0,-8)
(-2,-6) becomes (4,-6)
(-4,-2) becomes (2,-2)
and (-8,-4) becomes (-2,-4)
Hope this helped!
Evaluate the spherical coordinate integral
u=x+y , v= -2x + y;
∫ ∫ (-3x + 4y) dx dy
R
where R is the parallelogram bounded by the lines y = -x + 1, y = -x + 4, y = 2x + 2, y = 2x + 5
Rewrite the equations of the given boundary lines:
y = -x + 1 ==> x + y = 1
y = -x + 4 ==> x + y = 4
y = 2x + 2 ==> -2x + y = 2
y = 2x + 5 ==> -2x + y = 5
This tells us the parallelogram in the x-y plane corresponds to the rectangle in the u-v plane with 1 ≤ u ≤ 4 and 2 ≤ v ≤ 5.
Compute the Jacobian determinant for this change of coordinates:
[tex]J=\begin{bmatrix}\frac{\partial u}{\partial x}&\frac{\partial u}{\partial y}\\\frac{\partial v}{\partial x}&\frac{\partial v}{\partial y}\end{bmatrix}=\begin{bmatrix}1&1\\-2&1\end{bmatrix}\implies|\det J|=3[/tex]
Rewrite the integrand:
[tex]-3x+4y=-3\cdot\dfrac{u-v}3+4\cdot\dfrac{2u+v}3=\dfrac{5u+7v}3[/tex]
The integral is then
[tex]\displaystyle\iint_R(-3x+4y)\,\mathrm dx\,\mathrm dy=3\iint_{R'}\frac{5u+7v}3\,\mathrm du\,\mathrm dv=\int_2^5\int_1^45u+7v\,\mathrm du\,\mathrm dv=\boxed{333}[/tex]
my dad is designing a new garden. he has 21 feet of fencing to go around the garden. he wants the length of the garden to be 1 1/2 feet longer than the width. how wide should he make the garden?
Answer:
21=2w+2w+3 18=4w w=4.5
Please help! V^2 = 25/81
Answer:
C and D
Step-by-step explanation:
khan acedemy
An equation is formed when two equal expressions. The solutions to the given equation are A, B, and C.
What is an equation?An equation is formed when two equal expressions are equated together with the help of an equal sign '='.
The solution of the given equation v²=25/81 can be found as shown below.
v²=25/81
Taking the square root of both sides of the equation,
√(v²) = √(25/81)
v = √(25/81)
v = √(5² / 9²)
v = ± 5/9
Hence, the solutions of the given equation are A, B, and C.
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A fair die is rolled repeatedly. Calculate to at least two decimal places:__________
a) the chance that the first 6 appears before the tenth roll
b) the chance that the third 6 appears on the tenth roll
c) the chance of seeing three 6's among the first ten rolls given that there were six 6's among the first twenty roles.
d) the expected number of rolls until six 6's appear
e) the expected number of rolls until all six faces appear
Answer:
a. 0.34885
b. 0.04651
c. 0.02404
d. 36
e. 14.7, say 15 trials
Step-by-step explanation:
Q17070205
Note:
1. In order to be applicable to established probability distributions, each roll is considered a Bernouilli trial, i.e. has only two outcomes, success or failure, and are all independent of each other.
2. use R to find the probability values from the respective distributions.
a) the chance that the first 6 appears before the tenth roll
This means that a six appears exactly once between the first and the nineth roll.
Using binomial distribution, p=1/6, n=9, x=1
dbinom(1,9,1/6) = 0.34885
b) the chance that the third 6 appears on the tenth roll
This means exactly two six's appear between the first and 9th rolls, and the tenth roll is a six.
Again, we have a binomial distribution of p=1/6, n=9, x=2
p1 = dbinom(2,9,1/6) = 0.27908
The probability of the tenth roll being a 6 is, evidently, p2 = 1/6.
Thus the probability of both happening, by the multiplication rule, assuming independence
P(third on the tenth roll) = p1*p2 = 0.04651
c) the chance of seeing three 6's among the first ten rolls given that there were six 6's among the first twenty roles.
Again, using binomial distribution, probability of 3-6's in the first 10 rolls,
p1 = dbinom(3,10,1/6) = 0.15504
Probability of 3-6's in the NEXT 10 rolls
p1 = dbinom(3,10,1/6) = 0.15504
Probability of both happening (multiplication rule, assuming both events are independent)
= p1 * p1 = 0.02404
d) the expected number of rolls until six 6's appear
Using the negative binomial distribution, the expected number of failures before n=6 successes, with probability p = 1/6
= n(1-p)/p
Total number of rolls by adding n
= n(1-p)/p + n = n(1-p+p)/p = n/p = 6/(1/6) = 36
e) the expected number of rolls until all six faces appear
P1 = 6/6 because the firs trial (roll) can be any face with probability 1
P2 = 6/5 because the second trial for a different face has probability 5/6, so requires 6/5 trials
P3 = 6/4 ...
P4 = 6/3
P5 = 6/2
P6 = 6/1
So the total mean (expected) number of trials is 6/6+6/5+6/4+6/3+6/2+6/1 = 14.7, say 15 trials
The length of a rectangular garden is 3 yards greater
than the width of the garden. If the garden measures
15 yards diagonally, what is its length?
Answer:
12
Step-by-step explanation:
Let's call the width x and the length x + 3. Using the Pythagorean Theorem we can write:
(x + 3)² + x² = 15²
x² + 6x + 9 + x² = 225
2x² + 6x - 216 = 0
2(x² + 3x - 108) = 0
2(x + 12)(x - 9) = 0
x + 12 = 0 or x - 9 = 0
x = -12 or x = 9
x cannot be -12 because length/width can't be negative so x = 9 which means that the length is 9 + 3 = 12.