Question 1

When conducting a chi-square test for a goodness-of-fit, the number of degrees of freedom is given by __________.

Accepted Answer

The answer of When conducting a chi-square test for a...

Question 2

A small computed $X^{2}$ value for a contingency table reveals which of the following concerning the two variables?

Accepted Answer

A)  There is a strong relationship between them. 
B)  One is dependent on the other. 
C)  The observed frequencies greatly differ from the expected frequencies. 
D)  One is independent of the other.

Question 3

The null hypothesis in a chi-square test of independence is that there is no relationship between the two variables.

Accepted Answer

A) True 
 B)False

Question 4

If the observed frequencies are exactly equal to the expected frequencies in a chi-square test, the value of $X^{2}$ is

Accepted Answer

A)  close to 1 . 
B)  a large positive value. 
C)  0 . 
D)  a very small positive value.

Question 5

For a contingency table, the expected frequency values are based on the assumption that the null hypothesis is true.

Accepted Answer

A) True 
 B)False

Question 6

If $n=400$, an hypothesis test may be conducted to test a population proportion using the normal curve if $p$ is between __________ and __________.

Accepted Answer

The answer of If $n=400$, an hypothesis test may be...

Question 7

It is claimed that at most $70 \%$ of all local businesses last more than one year. The null hypothesis $p=0.70$ is tested against the alternative $p>0.70$ at $\alpha=0.05$ for a sample size of $n=11$. Suppose eight of the businesses lasted more than one year. Which of the following decisions should be made regarding the null hypothesis?

Accepted Answer

A)  Reject, since $11>8$. 
B)  Do not reject, since $11>8$. 
C)  Reject, since $8>4$. 
D)  Do not reject, since $8>4$.

Question 8

An office worker claims that at most $30 \%$ of the phone calls he makes are the nonbusiness type. Conduct a two-tailed test of $p=0.30$ at $\alpha=0.05$, if a random sample of 13 of his calls reveals 8 nonbusiness calls.

Accepted Answer

The answer of An office worker claims that at most...

Question 9

A cereal company is marketing a new breakfast food. In a random sample of 250 people who have tried the product, 175 said that they would buy it again. What can we state with $99 \%$ confidence about the maximum
size of our error if we use the sample proportion $\frac{175}{250}=0.70$ as an estimate of the actual population proportion of people who will buy the product a second time?

Accepted Answer

The answer of A cereal company is marketing a new...

Question 10

For a particular error value and confidence level, the maximum value that the sample size formula can assume occurs when $p$ equals __________.

Accepted Answer

The answer of For a particular error value and confidence...

Question 11

In determining the necessary sample size for $95 \%$ confidence interval, the value 0.95 must be substituted into the formula for $z_{\alpha / 2}$.

Accepted Answer

A) True 
 B)False

Question 12

A sample of 210 people were telephoned. The number of rings that have fully elapsed before each person answered the phone are recorded below.
 
-At the 0.05 level of significance, does it appear that the data may be looked upon as a random sample from a binomial population with $p=0.4$ and $n=6$ ? Conduct the goodness-of-fit test.

Accepted Answer

The answer of A sample of 210 people were telephoned....

Question 13

In a study to determine if a college student's year in college is independent of his or her major, a sample of 200 students was found to contain 40 juniors and 50 accounting majors. Then, the expected frequency of junior accounting majors is

Accepted Answer

A)  10 . 
B)  20 . 
C)  25 . 
D)  15 .

Question 14

A drug company wants to know whether the probability is really 0.20 that one of their products will produce side effects. In a random sample of 150 consumers of the product, 42 were victims of side effects. Conduct a one-tailed test where the alternative is that the probability is greater than 0.20 . Use $\alpha=0.01$.

Accepted Answer

The answer of A drug company wants to know whether...

Question 15

In order to use the maximum error of estimate formula involving the sample value $x / n, n$ must be large enough to justify the normal curve approximation to the binomial distribution.

Accepted Answer

A) True 
 B)False

Question 16

The $X^{2}$ statistic should never be applied to contingency tables if some of the expected frequencies are less than 5.

Accepted Answer

A) True 
 B)False

Question 17

A university placement office wants to estimate the percentage of graduates that obtain jobs within one month of graduation. They want to be $98 \%$ confident in their result and be within $5 \%$ of the true percentage. Find the necessary sample size for this experiment, and find a $98 \%$ confidence interval if $30 \%$ of the sample received jobs within one month of graduation.

Accepted Answer

The answer of A university placement office wants to estimate...

Question 18

The chi-square statistic for a $7 \times 4$ contingency table will have __________ degrees of freedom.

Accepted Answer

The answer of The chi-square statistic for a \(7 \times...

Question 19

The value of $\alpha$ has a definite effect on the number of degrees of freedom used to determine $\mathrm{X}^{2}$.

Accepted Answer

A) True 
 B)False

Question 20

A company is marketing a laser disk recorder. A survey of 80 randomly selected male students at a college reveals that 45 would be interested in buying such a recorder. A corresponding survey of 120 female students reveals that 75 want to buy it. Test the hypothesis that there is no difference between the males and the females on this issue. Use the $5 \%$ significance level.

Accepted Answer

The answer of A company is marketing a laser disk...

Exam 14: Tests of Hypotheses Based on Count Data

When conducting a chi-square test for a goodness-of-fit, the number of degrees of freedom is given by __________.

A small computed $X^{2}$ value for a contingency table reveals which of the following concerning the two variables?

The null hypothesis in a chi-square test of independence is that there is no relationship between the two variables.

If the observed frequencies are exactly equal to the expected frequencies in a chi-square test, the value of $X^{2}$ is

For a contingency table, the expected frequency values are based on the assumption that the null hypothesis is true.

If $n=400$ , an hypothesis test may be conducted to test a population proportion using the normal curve if $p$ is between and .

An office worker claims that at most $30 \%$ of the phone calls he makes are the nonbusiness type. Conduct a two-tailed test of $p=0.30$ at $\alpha=0.05$ , if a random sample of 13 of his calls reveals 8 nonbusiness calls.

For a particular error value and confidence level, the maximum value that the sample size formula can assume occurs when $p$ equals __________.

In determining the necessary sample size for $95 \%$ confidence interval, the value 0.95 must be substituted into the formula for $z_{\alpha / 2}$ .

In a study to determine if a college student's year in college is independent of his or her major, a sample of 200 students was found to contain 40 juniors and 50 accounting majors. Then, the expected frequency of junior accounting majors is

In order to use the maximum error of estimate formula involving the sample value $x / n, n$ must be large enough to justify the normal curve approximation to the binomial distribution.

The $X^{2}$ statistic should never be applied to contingency tables if some of the expected frequencies are less than 5.

The chi-square statistic for a $7 \times 4$ contingency table will have __________ degrees of freedom.

The value of $\alpha$ has a definite effect on the number of degrees of freedom used to determine $\mathrm{X}^{2}$ .

Exam 14: Tests of Hypotheses Based on Count Data

When conducting a chi-square test for a goodness-of-fit, the number of degrees of freedom is given by __________.

A small computed X2X^{2}X2 value for a contingency table reveals which of the following concerning the two variables?

The null hypothesis in a chi-square test of independence is that there is no relationship between the two variables.

If the observed frequencies are exactly equal to the expected frequencies in a chi-square test, the value of X2X^{2}X2 is

For a contingency table, the expected frequency values are based on the assumption that the null hypothesis is true.

If n=400n=400n=400 , an hypothesis test may be conducted to test a population proportion using the normal curve if ppp is between __________ and __________.

An office worker claims that at most 30%30 \%30% of the phone calls he makes are the nonbusiness type. Conduct a two-tailed test of p=0.30p=0.30p=0.30 at α=0.05\alpha=0.05α=0.05 , if a random sample of 13 of his calls reveals 8 nonbusiness calls.

For a particular error value and confidence level, the maximum value that the sample size formula can assume occurs when ppp equals __________.

In determining the necessary sample size for 95%95 \%95% confidence interval, the value 0.95 must be substituted into the formula for zα/2z_{\alpha / 2}zα/2​ .

In a study to determine if a college student's year in college is independent of his or her major, a sample of 200 students was found to contain 40 juniors and 50 accounting majors. Then, the expected frequency of junior accounting majors is

In order to use the maximum error of estimate formula involving the sample value x/n,nx / n, nx/n,n must be large enough to justify the normal curve approximation to the binomial distribution.

The X2X^{2}X2 statistic should never be applied to contingency tables if some of the expected frequencies are less than 5.

The chi-square statistic for a 7×47 \times 47×4 contingency table will have __________ degrees of freedom.

The value of α\alphaα has a definite effect on the number of degrees of freedom used to determine X2\mathrm{X}^{2}X2 .

A small computed $X^{2}$ value for a contingency table reveals which of the following concerning the two variables?

If the observed frequencies are exactly equal to the expected frequencies in a chi-square test, the value of $X^{2}$ is

If $n=400$ , an hypothesis test may be conducted to test a population proportion using the normal curve if $p$ is between and .

An office worker claims that at most $30 \%$ of the phone calls he makes are the nonbusiness type. Conduct a two-tailed test of $p=0.30$ at $\alpha=0.05$ , if a random sample of 13 of his calls reveals 8 nonbusiness calls.

For a particular error value and confidence level, the maximum value that the sample size formula can assume occurs when $p$ equals __________.

In determining the necessary sample size for $95 \%$ confidence interval, the value 0.95 must be substituted into the formula for $z_{\alpha / 2}$ .

In order to use the maximum error of estimate formula involving the sample value $x / n, n$ must be large enough to justify the normal curve approximation to the binomial distribution.

The $X^{2}$ statistic should never be applied to contingency tables if some of the expected frequencies are less than 5.

The chi-square statistic for a $7 \times 4$ contingency table will have __________ degrees of freedom.

The value of $\alpha$ has a definite effect on the number of degrees of freedom used to determine $\mathrm{X}^{2}$ .