Test identification Suppose you were asked to analyze each of the situations described below.
(NOTE: Do not do these problems!) For each, indicate which procedure you would use (pick the appropriate number from the list), the test statistic ( $z$, $t$, or $\chi ^ { 2 }$ "chi-squared"), and, if $t$ or $\chi ^ { 2 }$, the number of degrees of freedom. A choice may be used more than once.

1. proportion - 1 sample
2. difference of proportions - 2 samples
3. mean - 1 sample
4. difference of means - independent samples
5. mean of differences - matched pairs
6. goodness of fit
7. homogeneity
8. independence
a. A union organization would like to represent the employees at the local market. A
sample of the employees revealed 74 of 120 were in favor of the union. Does the union
have the required 3 to 2 majority?
b. An oral surgeon is interested in estimating how long it takes to extract all four wisdom
teeth. The doctor records the times for 24 randomly chosen surgeries. Estimate the time it
takes to perform the surgery with a 95% confidence interval.
c. A microwave manufacturing company receives large shipments of thermal shields from
two suppliers. A sample from each supplier's shipment is selected and tested for the rate of
defects. The microwave manufacturing company's contract with each supplier states the
shipment with the smallest rate of defect will be accepted. Do the shipments' defect rates
vary from each other?
d. The owner of a construction company would like to know if his current work teams can
build room additions quicker than the time allotted for by the contract. A random sample
of 15 room additions completed recently revealed an average completion time of 0.32 days
faster than contracted. Is this strong evidence that the teams can complete room additions
in less than the contract times?
e. A farmer would like to know if a new fertilizer increases his crop yield. In an effort to
decide this, the farmer recorded the yield for 10 different fields prior to adding fertilizer
and after adding the fertilizer. The farmer assumes the crop yields are approximately
normal. Does the fertilizer work as advertised?
f. A manufacturer gets parts from four suppliers (call them A, B, C, and D). A random
sample of 1000 parts is selected from shipments by each supplier. In the samples, Supplier
A has 21 defects, Supplier B has 14 defects, Supplier C has 8 defects, and Supplier D has 17
defects. Does this suggest any difference between the quality of parts provided by these
suppliers?
g. In a study to determine whether there is a difference between the average jail time
convicted bank robbers and car thieves are sentenced to, the law students randomly
selected 20 cases of each type that resulted in jail sentences during the previous year. A
90% confidence interval was created from the results..

Question

Test identification Suppose you were asked to analyze each of the situations described below.
(NOTE: Do not do these problems!) For each, indicate which procedure you would use (pick the appropriate number from the list), the test statistic ( $z$, $t$, or $\chi ^ { 2 }$ "chi-squared"), and, if $t$ or $\chi ^ { 2 }$, the number of degrees of freedom. A choice may be used more than once.

1. proportion - 1 sample
2. difference of proportions - 2 samples
3. mean - 1 sample
4. difference of means - independent samples
5. mean of differences - matched pairs
6. goodness of fit
7. homogeneity
8. independence 
a. A union organization would like to represent the employees at the local market. A
sample of the employees revealed 74 of 120 were in favor of the union. Does the union
have the required 3 to 2 majority?
b. An oral surgeon is interested in estimating how long it takes to extract all four wisdom
teeth. The doctor records the times for 24 randomly chosen surgeries. Estimate the time it
takes to perform the surgery with a 95% confidence interval.
c. A microwave manufacturing company receives large shipments of thermal shields from
two suppliers. A sample from each supplier's shipment is selected and tested for the rate of
defects. The microwave manufacturing company's contract with each supplier states the
shipment with the smallest rate of defect will be accepted. Do the shipments' defect rates
vary from each other?
d. The owner of a construction company would like to know if his current work teams can
build room additions quicker than the time allotted for by the contract. A random sample
of 15 room additions completed recently revealed an average completion time of 0.32 days
faster than contracted. Is this strong evidence that the teams can complete room additions
in less than the contract times?
e. A farmer would like to know if a new fertilizer increases his crop yield. In an effort to
decide this, the farmer recorded the yield for 10 different fields prior to adding fertilizer
and after adding the fertilizer. The farmer assumes the crop yields are approximately
normal. Does the fertilizer work as advertised?
f. A manufacturer gets parts from four suppliers (call them A, B, C, and D). A random
sample of 1000 parts is selected from shipments by each supplier. In the samples, Supplier
A has 21 defects, Supplier B has 14 defects, Supplier C has 8 defects, and Supplier D has 17
defects. Does this suggest any difference between the quality of parts provided by these
suppliers?
g. In a study to determine whether there is a difference between the average jail time
convicted bank robbers and car thieves are sentenced to, the law students randomly
selected 20 cases of each type that resulted in jail sentences during the previous year. A
90% confidence interval was created from the results..

Quizplus · Accepted Answer

The Answer of Test identification Suppose you were asked to analyze each of the situations described below.
(NOTE: Do not do these problems!) For each, indicate which procedure you would use (pick the appropriate number from the list), the test statistic ( $z$, $t$, or $\chi ^ { 2 }$ "chi-squared"), and, if $t$ or $\chi ^ { 2 }$, the number of degrees of freedom. A choice may be used more than once.

1. proportion - 1 sample
2. difference of proportions - 2 samples
3. mean - 1 sample
4. difference of means - independent samples
5. mean of differences - matched pairs
6. goodness of fit
7. homogeneity
8. independence 
a. A union organization would like to represent the employees at the local market. A
sample of the employees revealed 74 of 120 were in favor of the union. Does the union
have the required 3 to 2 majority?
b. An oral surgeon is interested in estimating how long it takes to extract all four wisdom
teeth. The doctor records the times for 24 randomly chosen surgeries. Estimate the time it
takes to perform the surgery with a 95% confidence interval.
c. A microwave manufacturing company receives large shipments of thermal shields from
two suppliers. A sample from each supplier's shipment is selected and tested for the rate of
defects. The microwave manufacturing company's contract with each supplier states the
shipment with the smallest rate of defect will be accepted. Do the shipments' defect rates
vary from each other?
d. The owner of a construction company would like to know if his current work teams can
build room additions quicker than the time allotted for by the contract. A random sample
of 15 room additions completed recently revealed an average completion time of 0.32 days
faster than contracted. Is this strong evidence that the teams can complete room additions
in less than the contract times?
e. A farmer would like to know if a new fertilizer increases his crop yield. In an effort to
decide this, the farmer recorded the yield for 10 different fields prior to adding fertilizer
and after adding the fertilizer. The farmer assumes the crop yields are approximately
normal. Does the fertilizer work as advertised?
f. A manufacturer gets parts from four suppliers (call them A, B, C, and D). A random
sample of 1000 parts is selected from shipments by each supplier. In the samples, Supplier
A has 21 defects, Supplier B has 14 defects, Supplier C has 8 defects, and Supplier D has 17
defects. Does this suggest any difference between the quality of parts provided by these
suppliers?
g. In a study to determine whether there is a difference between the average jail time
convicted bank robbers and car thieves are sentenced to, the law students randomly
selected 20 cases of each type that resulted in jail sentences during the previous year. A
90% confidence interval was created from the results..

Test Identification Suppose You Were Asked to Analyze Each of the Situations