In reference to the sample regression function y 025 008x1

In reference to the sample regression function:

y = -0.25 + 0.08x1 + 0.10x2

the value 0.08 is the

Select one:

a. predicted value of y

b. estimated change in y when x1 increases by one unit

c. estimated change in y when x2 increases by one unit

d. predicted value of y when x1 increases by one unit

e. predicted value of y when x2 increases by one unit

Question 20

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When testing the following null and alternative:

H₀: = 20

H_A: 20

the statistician calculated a sample mean of 19.20 and a sample standard deviation of 5, from a sample of 30.What is the test statistic?

Select one:

a. -0.16

b. -1.96

c. -0.8764

d. -0.8

Question 21

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The monthly electrical utility bills of all customers for Blue Ridge Electric are known to be distributed normally with a mean equal to $80.00 a month and a population standard deviation of $36.00.   If a sample of n = 100 customers is selected at random, what is the probability that the average bill for those sampled will exceed$75.00?   

Select one:

a. -1.39

b. 0.0823

c. 0.9177

d. 0.8795

Question 22

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Suppose a population dataset has a normal distribution.  Which of the following is true concerning the sampling distribution of the mean?

Select one:

a. It cannot be assumed normal

b. It will have the same standard deviation as the population distribution

c. It can be assumed normal only if the sample size is greater than or equal to 30

d. It can be assumed normal no matter the sample size

Solution

In reference to the sample regression function:

y = -0.25 + 0.08x1 + 0.10x2

the value 0.08 is the

Select one:

a. predicted value of y

b. estimated change in y when x1 increases by one unit

c. estimated change in y when x2 increases by one unit

d. predicted value of y when x1 increases by one unit

e. predicted value of y when x2 increases by one unit

Question 20

Question text

When testing the following null and alternative:

H₀: = 20

H_A: 20

the statistician calculated a sample mean of 19.20 and a sample standard deviation of 5, from a sample of 30.What is the test statistic?

Select one:

a. -0.16

b. -1.96

c. -0.8764

d. -0.8

t Test for Hypothesis of the Mean

Data

Null Hypothesis                m=

20

Level of Significance

0.05

Sample Size

30

Sample Mean

19.2

Sample Standard Deviation

5

Intermediate Calculations

Standard Error of the Mean

0.9129

Degrees of Freedom

29

t Test Statistic

-0.8764

Two-Tail Test

Lower Critical Value

-2.0452

Upper Critical Value

2.0452

p-Value

0.3880

Do not reject the null hypothesis

Question 21

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Points out of 4

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Question text

The monthly electrical utility bills of all customers for Blue Ridge Electric are known to be distributed normally with a mean equal to $80.00 a month and a population standard deviation of $36.00.   If a sample of n = 100 customers is selected at random, what is the probability that the average bill for those sampled will exceed$75.00?   

Select one:

a. -1.39

b. 0.0823

c. 0.9177

d. 0.8795

z value for 75, z=(75-80)/(36/sqrt(100)) =-1.39

P( mean x >75) = p( z > -1.39) =0.9177

Question 22

Not yet answered

Points out of 4

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Question text

Suppose a population dataset has a normal distribution.  Which of the following is true concerning the sampling distribution of the mean?

Select one:

a. It cannot be assumed normal

b. It will have the same standard deviation as the population distribution

c. It can be assumed normal only if the sample size is greater than or equal to 30

d. It can be assumed normal no matter the sample size

t Test for Hypothesis of the Mean
Data
Null Hypothesis                m=	20
Level of Significance	0.05
Sample Size	30
Sample Mean	19.2
Sample Standard Deviation	5
Intermediate Calculations
Standard Error of the Mean	0.9129
Degrees of Freedom	29
t Test Statistic	-0.8764
Two-Tail Test
Lower Critical Value	-2.0452
Upper Critical Value	2.0452
p-Value	0.3880
Do not reject the null hypothesis