Question 1

Use p-values to draw conclusions about hypothesis tests.
-On studying the database, the manufacturer found out that the average difference between the estimated and actual total costs was $394. Based on the sample data, can the manufacturer conclude that the average difference between the estimated and actual total costs is different from zero?

Accepted Answer

The answer of Use p-values to draw conclusions about hypothesis...

Question 2

State the proper forms of hypotheses for two-sample hypothesis tests.
-For a two-sample hypothesis test for differences in population parameters (1) and (2), which of the following is the correct form of an upper-tailed test?

Accepted Answer

In an upper-tailed test, the null hypothesis (H0) states that the difference is less than or equal to zero, while the alternative hypothesis (H1) states that the difference is greater than zero.

Question 3

Which of the following is true while applying the Excel ANOVA tool?

Accepted Answer

The input range must be a rectangular region that contains all data.

Question 4

If the alternative hypothesis includes the symbol <, the rejection region is in the upper tail.

Accepted Answer

The rejection region is in the lower tail when the alternative hypothesis includes the symbol <, indicating a left-tailed test.

Question 5

Use the data given below to answer the following question(s).
In a lower one-tailed hypothesis test, chosen level of significance = 0.10, sample size = 55, and t- test statistic = -1.76.
-For a two-sample hypothesis which tests for differences in population parameters (1) and (2), a two-tailed test seeks evidence that population parameter:

Accepted Answer

A two-tailed test seeks evidence that population parameter (2) is the same as parameter (1) as it tests whether there is a significant difference in the means of two populations. The given information about the lower one-tailed hypothesis test, level of significance, sample size, and t-test statistic is not relevant to this question.

Question 6

Which of the following 2010 Excel functions computes the p-value for the chi-square test?

Accepted Answer

The CHISQ.TEST function is used to calculate the p-value for chi-square tests. Choice A (CHISQ.INV.RT) calculates the right-tailed inverse of the chi-square distribution. Choice B (CHIDIST) calculates the probability that a random variable from the chi-square distribution falls within a specified range. Choice C (CHI.SQ) simply returns the chi-square statistic based on the given data.

Question 7

State the proper forms of hypotheses for two-sample hypothesis tests.
-For a lower-tail test, the p-value in the output from an Excel tool:

Accepted Answer

For a lower-tail test, the null hypothesis is that the population parameter is greater than or equal to the hypothesized value, while the alternative hypothesis is that the population parameter is less than the hypothesized value. Therefore, if the test-statistic is negative, it supports the alternative hypothesis and the p-value would be the probability of getting a test statistic as extreme or more extreme than the observed value, given that the null hypothesis is true.

Question 8

In order to reject the null hypothesis, the F-test statistic must be greater than the .

Accepted Answer

The F-test statistic must be greater than the critical value of F, which is determined by the degree of freedom and the significance level chosen. This critical value is also known as the F crit value. Therefore, choice D is the correct answer.

Question 9

Which of the following is true about chi-square distribution?

Accepted Answer

The chi-square distribution is characterized by degrees of freedom, which determines the shape of the distribution. It is denoted by (C²) is not a valid notation. The Excel function CHISQ.INV.TEST is used to obtain the p-value of a chi-square test, not to compute the distribution itself. The statement that the left-tail area is equal to the expected value of the sample is not true for the chi-square distribution.

Question 10

For a two-sample test for means with the population variance being known, the Excel procedure used is the Excel z-test.

Accepted Answer

The Excel procedure used for a two-sample test for means with known population variances is the Excel z-test.

Question 11

In a two-sample test for differences in means, the hypotheses are of the form:

Accepted Answer

The correct form of hypothesis in a two-sample test for differences in means is $ H_{0}: \mu_{1}-\mu_{2}= 0 $ and $ H_{1}: \mu_{1}-\mu_{2}\neq 0 $ or $ H_{1}: \mu_{1}- \mu_{2}>0 $ or $ H_{1}: \mu_{1} -\mu_{2} < 0 $. Option B correctly represents these hypotheses by allowing for a two-sided test ($ \neq $ in $ H_{1} $) and either directionality in the alternative hypothesis ($ > $ or $<$ in $ H_{1} $).

Question 12

State the proper forms of hypotheses for two-sample hypothesis tests. Select and use Excel Analysis Toolpak procedures for two-sample hypothesis tests.
-In conducting a hypothesis test, what is usually to be proven statistically is identified as the null hypothesis.

Accepted Answer

The answer of State the proper forms of hypotheses for...

Question 13

State the proper forms of hypotheses for two-sample hypothesis tests.
-Which of the following Excel tools is used for a two-sample test for equality of variances?

Accepted Answer

The Excel F-test Two-sample for variances is specifically designed to test the equality of variances between two samples.

Question 14

Which of the following tests is used to determine if two categorical variables are independent?

Accepted Answer

The chi-square test is used to determine if two categorical variables are independent. The other tests listed are used to compare means or test hypotheses about a single population parameter.

Question 15

Use the data given below to answer the following question(s).
The following extract from a manufacturer's database shows a sample of 10 suppliers, their transportation charges, and the estimated and actual total costs of supplying materials. (Note: Assume a significance level of 0.05 wherever necessary.) $$\begin{array} { | l | c | c | c | } 
\hline \text { Supp lier } & \begin{array} { c } 
\text { Transportation } \
\text { Charges }
\end{array} & \begin{array} { c } 
\text { Estimated Total } \
\text { Cost }
\end{array} & \begin{array} { c } 
\text { Actual Total } \
\text { Cost }
\end{array} \
\hline \text { Peter } & 340 & 4,500 & 4,680 \
\hline \text { John } & 560 & 4,500 & 4,790 \
\hline \text { Martin } & 480 & 4,500 & 5,110 \
\hline \text { Philip } & 290 & 4,500 & 4,780 \
\hline \text { Mark } & 370 & 4,500 & 4,810 \
\hline \text { Thomas } & 520 & 4,500 & 4,770 \
\hline \text { Jaison } & 350 & 4,500 & 5,250 \
\hline \text { David } & 430 & 4,500 & 4,930 \
\hline \text { Carter } & 510 & 4,500 & 5,010 \
\hline \text { Leonard } & 270 & 4,500 & 4,810 \
\hline
\end{array}$$
-Conduct the appropriate type of one-sample test-statistic to determine whether the average transportation charge is less than $430.

Accepted Answer

The answer of Use the data given below to answer...

Question 16

Use the data given below to answer the following question(s).
The following extract from a manufacturer's database shows a sample of 10 suppliers, their transportation charges, and the estimated and actual total costs of supplying materials. (Note: Assume a significance level of 0.05 wherever necessary.) $$\begin{array} { | l | c | c | c | } 
\hline \text { Supp lier } & \begin{array} { c } 
\text { Transportation } \
\text { Charges }
\end{array} & \begin{array} { c } 
\text { Estimated Total } \
\text { Cost }
\end{array} & \begin{array} { c } 
\text { Actual Total } \
\text { Cost }
\end{array} \
\hline \text { Peter } & 340 & 4,500 & 4,680 \
\hline \text { John } & 560 & 4,500 & 4,790 \
\hline \text { Martin } & 480 & 4,500 & 5,110 \
\hline \text { Philip } & 290 & 4,500 & 4,780 \
\hline \text { Mark } & 370 & 4,500 & 4,810 \
\hline \text { Thomas } & 520 & 4,500 & 4,770 \
\hline \text { Jaison } & 350 & 4,500 & 5,250 \
\hline \text { David } & 430 & 4,500 & 4,930 \
\hline \text { Carter } & 510 & 4,500 & 5,010 \
\hline \text { Leonard } & 270 & 4,500 & 4,810 \
\hline
\end{array}$$
-Conduct the appropriate type of one-sample test-statistic to determine whether the average transportation charge is less than $430. Apply a decision rule using the observed level of significance and draw a conclusion.

Accepted Answer

The answer of Use the data given below to answer...

Question 17

Use the data given below to answer the following question(s).
In a lower one-tailed hypothesis test, chosen level of significance = 0.10, sample size = 55, and t- test statistic = -1.76.
-Which of the following computes the test statistic for a one-sample test for proportions?

Accepted Answer

The formula given is the one-sample test statistic for proportions. The values provided in the question, such as significance level and sample size, suggest that this is a test for proportions rather than a t-test. Option A is the formula for a test of a single population mean, while option B does not include the term for the standard error of the sample proportion. Option D includes an incorrect calculation of the denominator. Therefore, the correct formula for the one-sample test statistic for proportions is given by option C.

Quiz 7: Statistical Inference

State the proper forms of hypotheses for two-sample hypothesis tests. -For a two-sample hypothesis test for differences in population parameters (1) and (2) , which of the following is the correct form of an upper-tailed test?

Which of the following is true while applying the Excel ANOVA tool?

If the alternative hypothesis includes the symbol <, the rejection region is in the upper tail.

Which of the following 2010 Excel functions computes the p-value for the chi-square test?

State the proper forms of hypotheses for two-sample hypothesis tests. -For a lower-tail test, the p-value in the output from an Excel tool:

In order to reject the null hypothesis, the F-test statistic must be greater than the .

Which of the following is true about chi-square distribution?

For a two-sample test for means with the population variance being known, the Excel procedure used is the Excel z-test.

In a two-sample test for differences in means, the hypotheses are of the form:

State the proper forms of hypotheses for two-sample hypothesis tests. Select and use Excel Analysis Toolpak procedures for two-sample hypothesis tests. -In conducting a hypothesis test, what is usually to be proven statistically is identified as the null hypothesis.

State the proper forms of hypotheses for two-sample hypothesis tests. -Which of the following Excel tools is used for a two-sample test for equality of variances?

Which of the following tests is used to determine if two categorical variables are independent?

Use the data given below to answer the following question(s) . In a lower one-tailed hypothesis test, chosen level of significance = 0.10, sample size = 55, and t- test statistic = -1.76. -Which of the following computes the test statistic for a one-sample test for proportions?