Question 1

Instruction 10-6
A buyer for a manufacturing plant suspects that his primary supplier of raw materials is overcharging.In order to determine if his suspicion is correct,he contacts a second supplier and asks for the prices on similar various materials.He wants to compare these prices with those of his primary supplier.The data collected is presented in the table below,with some summary statistics presented (all of these might not be necessary to answer the questions which follow).The buyer believes that the differences are normally distributed and will use this sample to perform an appropriate test at a level of significance of 0.01.
 $$\begin{array} { c c c r } 
\text { Material } & \begin{array} { c } 
\text { Primary } \
\text { Supplier }
\end{array} & \begin{array} { c } 
\text { Secondary } \
\text { Supplier }
\end{array} & \text { Difference } \
\hline  1& \$ 55 & \$ 45 & \$ 10 \
2 & \$ 48 & \$ 47 & \$ 1 \
3 & \$ 31 & \$ 32 & - \$ 1 \
4 & \$ 83 & \$ 77 & \$ 6 \
5 & \$ 37 & \$ 37 & \$ 0 \
6& \$ 55 & \$ 54 & \$ 1 \
\hline \hline \text { Sum: } &\$309&\$292&\$17\
\text { Sum of Squares. } & \$ 17,573 & \$ 15,472 & \$ 139
\end{array}$$
-Referring to Instruction 10-6,what is the 99% confidence interval estimate for the mean difference in prices?

Accepted Answer

The answer of Instruction 10-6
A buyer for a manufacturing plant...

Question 2

In testing for the differences between the means of two related populations,the ________ hypothesis is the hypothesis of "no differences".

Accepted Answer

The answer of In testing for the differences between the...

Question 3

Instruction 10-12
Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0.
-Referring to Instruction 10-12,what is the 95% confidence interval estimate for the difference in the two means?

Accepted Answer

The answer of Instruction 10-12
Two samples each of size 25...

Question 4

Instruction 10-12
Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0.
-Referring to Instruction 10-12,the computed t statistic is ________.

Accepted Answer

The answer of Instruction 10-12
Two samples each of size 25...

Question 5

Instruction 10-12 Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0. -Referring to Instruction 10-12,if you were interested in testing against the one-tailed alternative that μ₁ > μ₂ at the α = 0.01 level of significance,the null hypothesis would ________ .

Accepted Answer

The answer of Instruction 10-12
Two samples each of size 25...

Question 6

Instruction 10-12
Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0.
-Referring to Instruction 10-12,what is the 90% confidence interval estimate for the difference in the two means?

Accepted Answer

The answer of Instruction 10-12
Two samples each of size 25...

Question 7

In testing for the differences between the means of two related populations,you assume that the differences follow a ________ distribution.

Accepted Answer

The answer of In testing for the differences between the...

Question 8

When testing H₀: π₁ - π₂ ≥ 0 versus H₁: π₁ - π₂ < 0,the observed value of the Z test statistic was found to be -2.13.The p-value for this test is A)0.0166. B)0.0332. C)0.9668. D)0.9834.

Accepted Answer

The answer of When testing H₀: π₁ - π₂ ≥...

Question 9

Instruction 10-12
Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0.
-Referring to Instruction 10-12,the p-value for a two-tailed test whose computed t statistic is 2.50 is between ________ and ________.

Accepted Answer

The answer of Instruction 10-12
Two samples each of size 25...

Question 10

When testing H₀: π₁ - π₂ ≤ 0 versus H₁: π₁ - π₂ > 0,the observed value of the Z test statistic was found to be -2.13.The p-value for this test is A)0.0166. B)0.0332. C)0.9668. D)0.9834.

Accepted Answer

The answer of When testing H₀: π₁ - π₂ ≤...

Question 11

Instruction 10-6
A buyer for a manufacturing plant suspects that his primary supplier of raw materials is overcharging.In order to determine if his suspicion is correct,he contacts a second supplier and asks for the prices on similar various materials.He wants to compare these prices with those of his primary supplier.The data collected is presented in the table below,with some summary statistics presented (all of these might not be necessary to answer the questions which follow).The buyer believes that the differences are normally distributed and will use this sample to perform an appropriate test at a level of significance of 0.01.
 $$\begin{array} { c c c r } 
\text { Material } & \begin{array} { c } 
\text { Primary } \
\text { Supplier }
\end{array} & \begin{array} { c } 
\text { Secondary } \
\text { Supplier }
\end{array} & \text { Difference } \
\hline  1& \$ 55 & \$ 45 & \$ 10 \
2 & \$ 48 & \$ 47 & \$ 1 \
3 & \$ 31 & \$ 32 & - \$ 1 \
4 & \$ 83 & \$ 77 & \$ 6 \
5 & \$ 37 & \$ 37 & \$ 0 \
6& \$ 55 & \$ 54 & \$ 1 \
\hline \hline \text { Sum: } &\$309&\$292&\$17\
\text { Sum of Squares. } & \$ 17,573 & \$ 15,472 & \$ 139
\end{array}$$
-Referring to Instruction 10-6,what is the 90% confidence interval estimate for the mean difference in prices?

Accepted Answer

The answer of Instruction 10-6
A buyer for a manufacturing plant...

Question 12

Instruction 10-12
Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0.
-Referring to Instruction 10-12,a two-tailed test of the null hypothesis of no difference would ________ (be rejected/not be rejected)at the α= 0.05 level of significance.

Accepted Answer

The answer of Instruction 10-12
Two samples each of size 25...

Question 13

In testing for the differences between the means of two independent populations,you assume that the two populations each follow a ________ distribution.

Accepted Answer

The answer of In testing for the differences between the...

Question 14

Instruction 10-6
A buyer for a manufacturing plant suspects that his primary supplier of raw materials is overcharging.In order to determine if his suspicion is correct,he contacts a second supplier and asks for the prices on similar various materials.He wants to compare these prices with those of his primary supplier.The data collected is presented in the table below,with some summary statistics presented (all of these might not be necessary to answer the questions which follow).The buyer believes that the differences are normally distributed and will use this sample to perform an appropriate test at a level of significance of 0.01.
 $$\begin{array} { c c c r } 
\text { Material } & \begin{array} { c } 
\text { Primary } \
\text { Supplier }
\end{array} & \begin{array} { c } 
\text { Secondary } \
\text { Supplier }
\end{array} & \text { Difference } \
\hline  1& \$ 55 & \$ 45 & \$ 10 \
2 & \$ 48 & \$ 47 & \$ 1 \
3 & \$ 31 & \$ 32 & - \$ 1 \
4 & \$ 83 & \$ 77 & \$ 6 \
5 & \$ 37 & \$ 37 & \$ 0 \
6& \$ 55 & \$ 54 & \$ 1 \
\hline \hline \text { Sum: } &\$309&\$292&\$17\
\text { Sum of Squares. } & \$ 17,573 & \$ 15,472 & \$ 139
\end{array}$$
-Referring to Instruction 10-6,what is the 95% confidence interval estimate for the mean difference in prices?

Accepted Answer

The answer of Instruction 10-6
A buyer for a manufacturing plant...

Question 15

When testing H₀: π₁ - π₂ = 0 versus H₁: π₁ - π₂ ≠ 0,the observed value of the Z test statistic was found to be -2.13.The p-value for this test is A)0.0166. B)0.0332. C)0.9668. D)0.9834.

Accepted Answer

The answer of When testing H₀: π₁ - π₂ =...

Question 16

Instruction 10-12
Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0.
-Referring to Instruction 10-12,there are ________ degrees of freedom for this test.

Accepted Answer

The answer of Instruction 10-12
Two samples each of size 25...

Question 17

Instruction 10-12
Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0.
-Referring to Instruction 10-12,the pooled (i.e. ,combined)variance is ________.

Accepted Answer

The answer of Instruction 10-12
Two samples each of size 25...

Question 18

Instruction 10-12
Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0.
-Referring to Instruction 10-12,the critical values for a two-tailed test of the null hypothesis of no difference in the population means at the α = 0.05 level of significance are ________.

Accepted Answer

The answer of Instruction 10-12
Two samples each of size 25...

Question 19

Instruction 10-12
Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0.
-Referring to Instruction 10-12,what is the 99% confidence interval estimate for the difference in the two means?

Accepted Answer

The answer of Instruction 10-12
Two samples each of size 25...

Question 20

Instruction 10-12
Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0.
-Referring to Instruction 10-12,the p-value for a one-tailed test whose computed statistic is 2.50 (in the hypothesised direction)is between ________ and ________.

Accepted Answer

The answer of Instruction 10-12
Two samples each of size 25...

Quiz 10: Hypothesis Testing: Two Sample Tests

In testing for the differences between the means of two related populations,the ________ hypothesis is the hypothesis of "no differences".

In testing for the differences between the means of two related populations,you assume that the differences follow a ________ distribution.

When testing H0: π1 - π2 ≥ 0 versus H1: π1 - π2 < 0,the observed value of the Z test statistic was found to be -2.13.The p-value for this test is

When testing H0: π1 - π2 ≤ 0 versus H1: π1 - π2 > 0,the observed value of the Z test statistic was found to be -2.13.The p-value for this test is

In testing for the differences between the means of two independent populations,you assume that the two populations each follow a ________ distribution.

When testing H0: π1 - π2 = 0 versus H1: π1 - π2 ≠ 0,the observed value of the Z test statistic was found to be -2.13.The p-value for this test is

When testing H₀: π₁ - π₂ ≥ 0 versus H₁: π₁ - π₂ < 0,the observed value of the Z test statistic was found to be -2.13.The p-value for this test is

When testing H₀: π₁ - π₂ ≤ 0 versus H₁: π₁ - π₂ > 0,the observed value of the Z test statistic was found to be -2.13.The p-value for this test is

When testing H₀: π₁ - π₂ = 0 versus H₁: π₁ - π₂ ≠ 0,the observed value of the Z test statistic was found to be -2.13.The p-value for this test is