Answer:
a) No sufficient evidence to support the claim that the two machines produce rods with different mean diameters.
b) P-value is 0.80
c) −0.3939 <μ< 0.4939
Step-by-step explanation:
Given Data:
sample sizes
n1 = 15
n2 = 17
sample means:
x1 = 8.73
x2 = 8.68
sample variances:
s1² = 0.35
s2² = 0.40
Hypothesis:
H₀ : μ₁ = μ₂
H₁ : μ₁ ≠ μ₂
Compute the pooled standard deviation:
[tex]s_{p} = \sqrt{\frac{(n_{1} - 1)s_{1}^{2} + (n_{2} - 1)s_{2}^{2}}{n_{1} +n_{2} -2} }[/tex]
[tex]= \sqrt{\frac{(15-1)0.35+(17-1)0.40}{15+7-2}}[/tex]
[tex]= \sqrt{\frac{(14)0.35+(16)0.40}{30}}[/tex]
[tex]= \sqrt{\frac{4.9+6.4}{30}}[/tex]
[tex]= \sqrt{\frac{11.3}{30}}[/tex]
[tex]= \sqrt{0.376667}[/tex]
= 0.613732
= 0.6137
Compute the test statistic:
[tex]t = \frac{x_{1} -x_{2} }{s_{p} \sqrt{\frac{1}{n_{1} }+\frac{1}{n_{2} } } }[/tex]
[tex]= \frac{8.73-8.68}{0.6137\sqrt{\frac{1}{15}+\frac{1}{17} } }[/tex]
[tex]= \frac{0.05}{0.6137\sqrt{0.06667+0.05882} } }[/tex]
[tex]= \frac{0.05}{0.6137\sqrt{0.12549} } }[/tex]
[tex]= \frac{0.05}{0.6137(0.354246)} } }[/tex]
[tex]= \frac{0.05}{0.6137(0.354246)} } }[/tex]
= 0.05 / 0.217401
= 0.22999
t = 0.230
Compute degree of freedom:
df = n1 + n2 -2 = 15 + 17 - 2 = 30
Compute the P-value from table using df = 30
P > 2 * 0.40 = 0.80
P > 0.05 ⇒ Fail to reject H₀
Null hypothesis is rejected when P-value is less than or equals to level of significance. But here the P-value = 0.80 and level of significance = 0.05. So P-value is greater than significance level. Hence there is not sufficient evidence to support the claim that population means are different.
Construct a 95% confidence interval for the difference in mean rod diameter:
confidence = c = 95% = 0.95
α = 1 - c
= 1 - 0.95
α = 0.05
Compute degree of freedom:
df = n1 + n2 -2 = 15 + 17 - 2 = 30
Compute [tex]t_{\alpha /2}[/tex] with df = 30 using table:
t₀.₀₂₅ = 2.042
Compute confidence interval:
= [tex](x_{1}-x_{2})-t_{\alpha/2} ( s_{p} )\sqrt{\frac{1}{n_{1} }+\frac{1}{n_{2} } }[/tex]
= (8.73 - 8.68) - 2.042 ( 0.6137 ) [tex]\sqrt{\frac{1}{15} +\frac{1}{17} }[/tex]
= 0.05 - 2.042 ( 0.6137 ) [tex]\sqrt{\frac{1}{15} +\frac{1}{17} }[/tex]
= 0.05 - 1.253175 [tex]\sqrt{0.06667+0.05882} } }[/tex]
= 0.05 - 1.253175 [tex]\sqrt{0.12549} } }[/tex]
= 0.05 - 1.253175 (0.35424))
= 0.05 - 0.443925
= −0.393925
= −0.3939
[tex](x_{1}-x_{2})+t_{\alpha/2} ( s_{p} )\sqrt{\frac{1}{n_{1} }+\frac{1}{n_{2} } }[/tex]
= (8.73 - 8.68) + 2.042 ( 0.6137 ) [tex]\sqrt{\frac{1}{15} +\frac{1}{17} }[/tex]
= 0.05 + 2.042 ( 0.6137 ) [tex]\sqrt{\frac{1}{15} +\frac{1}{17} }[/tex]
= 0.05 + 1.253175 [tex]\sqrt{0.06667+0.05882} } }[/tex]
= 0.05 + 1.253175 [tex]\sqrt{0.12549} } }[/tex]
= 0.05 + 1.253175 (0.35424))
= 0.05 + 0.443925
= 0.493925
= 0.4939
−0.3939 <μ₁ - μ₂< 0.4939
A soccer player has made 3 of her last 10 field goals, which is a field goal percentage of 30%. How many more consecutive field goals would she need to make to raise her field goal percentage to 50%?
Answer:
4 consecutive goals
Step-by-step explanation:
If 3 of last 10 field goals = 30%
Which is equivalent to
(Number of goals scored / total games played) * 100%
(3 / 10) * 100% = 30%
Number of consecutive goals one has to score to raise field goal to 50% will be:
Let y = number of consecutive goals
[(3+y) / (10+y)] * 100% = 50%
[(3+y) / (10+y)] * 100/100 = 50/100
[(3+y) / (10+y)] * 1 = 0.5
(3+y) / (10+y) = 0.5
3+y = 0.5(10 + y)
3+y = 5 + 0.5y
y - 0.5y = 5 - 3
0.5y = 2
y = 2 / 0.5
y = 4
Therefore, number of consecutive goals needed to raise field goal to 50% = 4
cindy was asked by her teacher to subtract 3 from a certain number and then divide the result by 6 instead, she subtracted 6 and then divided the result by 3 giving an answer of 25 what would her answer have been if she had worked the problem correctly?
Answer:
13
Step-by-step explanation:
let the number be x
how Cindy worked it out :
(x -6) ÷ 3 = 25
x -6 = 75
x = 81
How she should have worked it out:
(x - 3) ÷ 6
(81 - 3) ÷ 6
78 ÷ 6 = 13
If x = -1 then how much is 2x - 1
a) 1
b) -3
c) -2
hurry please need to turn in 10 min
Answer: -3
Step-by-step explanation: 2x = -2 then you subtract 1 from that which is the same as adding negative one so -2 - 1 or -2 + -1 = -3
Each wagon in the Parley
Company of Travelers wagon
train was about 3.65 meters long.
If 12 wagons traveled end to
end, how long would the wagon
train be?
Answer:
43.8 meters
Step-by-step explanation:
12 x 3.65
PLEASE HELP NOW
Solve the equation for y. Identify the slope and y-intercept then graph the equation.
2y-3x=10
Y=
M=
B=
Please Include a picture of the graph and show your work if you can
Answer:
Step-by-step explanation:
Solve for y:
[tex]2y-3x=10\\2y=3x+10\\y=\frac{3}{2} x+5[/tex]
Therefore:
y = 3/2x + 5
m = 3/2
b = 5
Graph below courtesy of Desmos.
Which expression defines the given series for seven terms?
–4 + (–5) + (–6) + . . .
Answer: -n+(-n-1)
Step-by-step explanation:
Expression will be -n + (-1)
Series
-4 +(-5)+(-6)+(-7)+(-8)+(-9)+(-10)+(-11)+(-12)+(-13) and so on
Here number -n has + (-n-1) being added to it
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Sin tita= 0.6892.find the value Of tita correct to two decimal places
Answer:
[tex]\theta \approx 6.28n + 2.38, \quad n \in \mathbb{Z}[/tex]
or
[tex]\theta \approx 6.28n + 0.76, \quad n \in \mathbb{Z}[/tex]
Considering [tex]\theta \in (0, 2\pi][/tex]
[tex]\theta \approx 2.38[/tex]
or
[tex]\theta \approx 0.76[/tex]
Step-by-step explanation:
[tex]\sin(\theta)=0.6892[/tex]
We have:
[tex]\sin (x)=a \Longrightarrow x=\arcsin (a)+2\pi n \text{ or } x=\pi -\arcsin (a)+2\pi n \text{ as } n\in \mathbb{Z}[/tex]
Therefore,
[tex]\theta= \arcsin (0.6892)+2\pi n, \quad n \in \mathbb{Z}[/tex]
or
[tex]\theta = \pi -\arcsin (0.6892)+2\pi n, \quad n\in \mathbb{Z}[/tex]
---------------------------------
[tex]\theta \approx 6.28n + 2.38, \quad n \in \mathbb{Z}[/tex]
or
[tex]\theta \approx 6.28n + 0.76, \quad n \in \mathbb{Z}[/tex]
A researcher at the University of Washington medical school believes that energy drink consumption may increase heart rate. Suppose it is known that heart rate (in beats per minute) is normally distributed with an average of 70 bpm for adults. A random sample of 25 adults was selected and it was found that their average heartbeat was 73 bpm after energy drink consumption, with a standard deviation of 7 bpm. In order to test belief at the 10% significance level, determine P-value for the test.
Answer:
Step-by-step explanation:
Given that:
mean μ = 70
sample size = 25
sample mean = 73
standard deviation = 7
level of significance = 0.10
The null hypothesis and the alternative hypothesis can be computed as follows:
[tex]\mathtt{H_o : \mu = 70} \\ \\ \mathtt{H_1 : \mu > 70 }[/tex]
The z score for this statistics can be calculated by using the formula:
[tex]z = \dfrac{X- \mu}{\dfrac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \dfrac{73- 70}{\dfrac{7}{\sqrt{25}}}[/tex]
[tex]z = \dfrac{3}{\dfrac{7}{5}}[/tex]
[tex]z = \dfrac{3 \times 5}{{7}{}}[/tex]
z = 2.143
At level of significance of 0.10
degree of freedom = n -1
degree of freedom = 25 - 1
degree of freedom = 24
The p - value from the z score at level of significance of 0.10 and degree of freedom of 24 is:
P - value = 1 - (Z < 2.143)
P - value = 1 - 0.9839
P - value = 0.0161
Decision Rule: since P value is lesser than the level of significance, we reject the null hypothesis.
Conclusion: We conclude that energy drink consumption increases heart rate.
Mr. Lock bought 6 quarts of oil for his car. He spent $16.02. How much was each quart of oil?
Answer:
2.67
Step-by-step explanation:
To solve this problem do 16.02 / 6.
I hope this answer helps you out! Brainliest woudl be appreciated.Janet has 8 points after the first round of the same game. how far does she travel to get to 2 points?
Answer:
Step-by-step explanation:
8-2=6
answer is 6
Answer:
2 x 4
Step-by-step explanation:
She need to travel 4 times before she reach the same points again
What number must be added to the expression below to complete the square? x2-5x
Answer:
6.25
Step-by-step explanation:
(x-a)^2=x^2-2ax+a^2
2a=5
a=2.5
2.5 ^ 2 = 6.25
Please answer this correctly without making mistakes
Answer:
[tex]\large \boxed{\mathrm{1/2 \ boxes}}[/tex]
Step-by-step explanation:
Subtract the fractions.
[tex]\frac{9}{16}-\frac{1}{16}=\frac{8}{16} =\frac{1}{2}[/tex]
Vicky had 1/2 of a box more baking powder yesterday.
a sheet metal worker earns $26.80 per hour after receiving a 4.5% raise. what was the sheet metal worker's hourly pay before raise? Round your answer to the nearest cent
Answer
$25.59
Step-by-step explanation:
subtract by percentage or you can also do:
100% - 4.5% = 95.5%
95.5% x $26.80 = $25.594
IF ROUNDED: $25.59
Answer:
$25.65
Step-by-step explanation:
Let the original hourly rate be r.
Then 1.045r + $26.80/hr.
Dividing both sides by 1.045, we get:
$26.80/hr
r = ------------------ = $25.65 This was the before-raise pay rate.
1.045
IV. Round to the nearest ten thousand
31. 41,876
32. 260,098
33. 91,975
34. 207,865
35. 462,876
Help!!! Make brainliest
Answer:
b=(2a-1)/(3a-1)
Step-by-step explanation:
a=(b-1)/(3b-2)
3ab-2a=b-1
3ab-b=2a-1
b(3a-1)=2a-1
b=(2a-1)/(3a-1)
the square of a number is 3 less than four times the number. which values could be the number?
Answer:
x could be 3 or 1
Step-by-step explanation:
x²+3=4x
x²-4x+3=0
(x-3)(x-1)
x could be 3 or 1
The values could be 1 or 3.
Let the number be n.In this exercise, you're required to write a mathematical (algebraic) expression for the given word problem and determine which values could be the unknown number.
Translating the word problem into an algebraic expression, we have;
[tex]n^{2} = 4n - 3\\\\n^{2} - 4n + 3 = 0[/tex]
We would solve the quadratic equation by using the factorization method;
[tex]n^{2} - 3n -n + 3 = 0\\\\n(n - 3) - 1(n - 3) = 0\\\\(n - 1)(n - 3) = 0[/tex]
Therefore, the values could be 1 or 3.
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What is the minimum sample size required to estimate a population mean with 90% confidence when the desired margin of error is 1.25
Complete Question
What is the minimum sample size required to estimate a population mean with 90% confidence when the desired margin of error is 1.25? The standard deviation in a pre-selected sample is 7.5
Answer:
The minimum sample size is [tex]n =97[/tex]
Step-by-step explanation:
From the question we are told that
The margin of error is [tex]E = 1.25[/tex]
The standard deviation is [tex]s = 7.5[/tex]
Given that the confidence level is 90% then the level of significance is mathematically represented as
[tex]\alpha = 100 - 90[/tex]
[tex]\alpha =10\%[/tex]
[tex]\alpha =0.10[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the normal distribution table
The value is [tex]Z_{\frac{ \alpha }{2} } = 1.645[/tex]
The minimum sample size is mathematically evaluated as
[tex]n = \frac{Z_{\frac{\alpha }{2} * s^2 }}{E^2 }[/tex]
=> [tex]n = \frac{1.645^2 * 7.5^2 }{1.25^2 }[/tex]
=> [tex]n =97[/tex]
Which of the following graphs accurately displays a parabola with its directrix and focus?
Answer:
Hey there!
The first graph is the correct answer. A point on the parabola is equally far from the focus as it is to the directrix.
Let me know if this helps :)
The graph that accurately displays a parabola with its directrix and focus is the first graph.
How do we make graph of a function?Suppose the considered function whose graph is to be made is f(x)
The values of 'x' (also called input variable, or independent variable) are usually plotted on horizontal axis, and the output values f(x) are plotted on the vertical axis.
They are together plotted on the point (x,y) = (x, f(x))
This is why we usually write the functions as: y = f(x)
A point shown in the graphs on the parabola is equally far from the focus as it is to the directrix.
Therefore, The first graph is the correct answer.
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The length of the hypotenuse of a 30 -60 -90 triangle is 32. What are the lengths of the legs?
Answer:
16, 16(sqrt3)
Step-by-step explanation:
30-60-90 triangles follow a rule where the hypotenuse is 2 times the shortest leg, and the longer leg is sqrt3 times the shorter leg.
So, the sides are x, 2x, and (sqrt3)x.
If 2x = 32, then x = 16.
Therefore the two legs are 16 and 16(sqrt3)
you can search up 30-60-90 triangle for more information
Find the measure of F. A. 44 B. 88 C. 90 D. 46
Answer:
A. 44º
Step-by-step explanation:
The sum of internal angles in a triangle is equal to 180 degrees, whereas the sum for a square is equal to 360 degrees. Given that three triangles depicted on figure constructs a square, it is to conclude that each is an isosceles triangle. The following relations are presented:
1) [tex]e + 92^{\circ} = 180^{\circ}[/tex] Given
2) [tex]a = b[/tex], [tex]c = d[/tex] Given
3) [tex]a + b + 92^{\circ} = 180^{\circ}[/tex] Given.
4) [tex]c + d + e = 180^{\circ}[/tex] Given.
5) [tex]b + c = 90^{\circ}[/tex] Given.
6) [tex]2\cdot a + 92^{\circ} = 180^{\circ}[/tex] 2) in 3)
7) [tex]a = 44^{\circ}[/tex] Algebra
8) [tex]b = 44^{\circ}[/tex] By 2)
9) [tex]b= f[/tex] Alternate internior angles.
10) [tex]f = 44^{\circ}[/tex] By 8). Result
Hence, the answer is A.
A height is labeled on the triangle below.
Which line segment shows the base that corresponds to the given height of the triangle
Option A,B,C
Answer:
A
Step-by-step explanation:
The height is always perpinducular to the base. The height here is perpendicular to line segment A.
Answer:
A
Step-by-step explanation:
Which point lies on the line with point-slope equation y - 3 = 4(x + 7)?
A.
(7, 3)
B.
(7, -3)
C.
(-7, -3)
D.
(-7, 3)
Answer:
D. (-7, 3)
Step-by-step explanation:
The equation given is in point-slope form.
Point-slope form is:
y-y1=m(x-x1)
This is where:
y1 is the y-coordinate of a point it goes through
m is the slope of the line
x1 is the x-coordinate of a point that it goes through
That said, in the given equation:
y1=3
m=4
x1=-7
Note that a point is (x-coordinate, y-coordinate)
Therefore, (-7, 3) is the point that lies on the line.
Assume that the following confidence interval for the difference in the mean length of male babies (sample 1) and female babies (sample 2) at birth was constructed using independent simple random samples:0.2 in2.7 in. What does the confidence interval suggest about the difference in length between male babies and female babies?
Answer:
The confidence interval consist of positive values, it implies that the mean length of male babies at birth is more than that of female babies.
Step-by-step explanation:
Consider the hypothesis for testing the difference in the mean length of male babies and female babies at birth:
H₀: There is no significant difference between the mean length of male babies and female babies at birth, i.e. μ₁ - μ₂ = 0.
Hₐ: There is a significant difference between the mean length of male babies and female babies at birth, i.e. μ₁ - μ₂ ≠ 0.
The decision rule based on the confidence interval is:
If the (1 - α)% confidence interval does not consist of the null value, i.e. 0 then the null hypothesis will be rejected.
The confidence interval for the difference in the mean length of male babies and female babies at birth is:
CI = (0.2 in, 2.7 in)
The confidence interval does not consist of the null value, i.e. 0.
Thus, the null hypothesis will be rejected.
Hence, concluding that there is a significant difference between the mean length of male babies and female babies at birth.
Since the confidence interval consist of positive values, it implies that the mean length of male babies at birth is more than that of female babies.
8. Point Mis 6 units away from the origin. Circle the letter by each pair of possible coordinates. A. (3.0) B. (4.2) C. (5,3) D. (0.6) E. (4.4) F. (1,5)
9514 1404 393
Answer:
D. (0, 6)
Step-by-step explanation:
The origin is where the axes cross. The coordinates of that point are (0, 0). The distance of a point (x2, y2) from point (x1, y1) is given by the distance formula ...
d = √((x2 -x1)² +(y2 -y1)²)
When (x1, y1) = (0, 0), this reduces to ...
d = √(x² +y²)
We want to find (x, y) such that d=6. This can be a little easier if we square both sides of the equation to eliminate the radical.
x² +y² = 6² = 36
This is the equation of a circle of radius 6 centered at the origin: all points that are distance 6 from the origin. So, any point on the circle will be at a distance of 6 from the origin.
__
The sum of squares in each case is ...
A. 3² +0² = 9 . . . inside the circle
B. 4² +2² = 20 . . . inside the circle
C. 5² +3² = 34 . . . inside the circle
D. 0² +6² = 36 . . . on the circle at a distance of 6 from the origin
E. 4² +4² = 32 . . . inside the circle
F. 1² +5² = 26 . . . inside the circle
The lengths of pregnancies in a small rural village are normally distributed with a mean of 265 days and a standard deviation of 14 days. In what range would we expect to find the middle 50% of most lengths of pregnancies
Answer:
the middle 50% of most lengths of pregnancies ranges between 255.62 days and 274.38 days
Step-by-step explanation:
Given that :
Mean = 265
standard deviation = 14
The formula for calculating the z score is [tex]z = \dfrac{x -\mu}{\sigma}[/tex]
x = μ + σz
At middle of 50% i.e 0.50
The critical value for [tex]z_{\alpha/2} = z_{0.50/2}[/tex]
From standard normal table
[tex]z_{0.25}=[/tex] + 0.67 or -0.67
So; when z = -0.67
x = μ + σz
x = 265 + 14(-0.67)
x = 265 -9.38
x = 255.62
when z = +0.67
x = μ + σz
x = 265 + 14 (0.67)
x = 265 + 9.38
x = 274.38
the middle 50% of most lengths of pregnancies ranges between 255.62 days and 274.38 days
Michael records the height of 1000 people. This data is a normal distribution and the sample mean was 0.75. Identify the margin of error for this data set.
Answer:
0.0284Step-by-step explanation:
The formula for calculating the Margin of error of a dataset is expressed as;
Margin of error = [tex]Z*\sqrt{\frac{p(1-p)}{n} } \\\\[/tex] where;
Z is the z-score of 95% confidence interval = 1.96
p is the sample proportion/mean = 0.75
n is the sample size = total number of people = 1000
Note that when the confidence interval is not given, it is always safe to use 95% confidence.
Substituting this values into the formula we have;
[tex]ME = 1.96*\sqrt{\frac{0.7(1-0.7)}{1000} } \\\\ME = 1.96*\sqrt{\frac{0.7(0.3)}{1000} } \\\\ME = 1.96*\sqrt{0.00021} } \\\\ME = 1.96*0.01449\\\\ME = 0.0284[/tex]
Hence the margin error for the dataset is 0.0284
resolve 2x^2+5x-1÷x(x-1)(x+2) into partial fractions.
AB is dilated from the origin to create A'B' at A' (0, 8) and B' (8, 12). What scale factor was AB dilated by?
Answer:
4
Step-by-step explanation:
Original coordinates:
A (0, 2)
B (2, 3)
The scale is what number the original coordinates was multiplied by to reach the new coordinates
1. Divide
(0, 8) ÷ (0, 2) = 4
(8, 12) ÷ (2, 3) = 4
AB was dilated by a scale factor of 4.
A garden plot turned out to be a trapezoid whose parallel sides
measured 18 feet and 42 feet respectively. The garden is 12 feet wide.
What is the area of the garden plot?
Select one:
n
O a. 720 ft?
b. 9,072 ft2
O c. 42 ft?
O d. 360 ft
Answer:
Step-by-step explanation:
Trapezoid area is the Average of the parallel lines times the width
A = ½(18 + 42)(12) = 360 ft²
The area of the garden plot is 360 ft².
What is Trapezoid?
A trapezoid is a four-sided closed 2D figure which has an area and its perimeter. Two sides of the shape are parallel to each other and they are termed as the bases of the trapezoid.
Here, the length of parallel sides = 18ft. and 42 ft.
Width of plot = 12 ft.
Area of Trapezoid = 1/2 X (b₁+b₂) X h
= 1/2 X (18 + 42) X 12
= 6 X 60
= 360 sq. ft.
Thus, the area of the garden plot is 360 ft².
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Which is the equation of the line with slope o passing through the point (-3,-1)?
9514 1404 393
Answer:
y = -1
Step-by-step explanation:
We assume you want the line with a slope of zero. That is a horizontal line, so y is a constant. In order to make the line go through the point with y=-1, the equation of the line is ...
y = -1