Question 1

Suppose that a medical study found a statistically significant relationship between wearing gold jewelry and developing skin cancer.Suppose the study was based on a sample of 100,000 people and had a p-value of .049.How would you react to these results?

Accepted Answer

C is correct because a large sample size can indeed make even very small and potentially insignificant relationships appear statistically significant, as indicated by a p-value just below the common threshold of .05. This can lead to misleading conclusions about the strength or importance of the relationship.

Question 2

Is it possible for an important relationship in a population to fail to achieve statistical significance in the sample and therefore go undetected, even if the sample is selected properly and the data are collected correctly? Explain your answer.

Accepted Answer

The answer of Is it possible for an important relationship...

Question 3

For Questions , use the following narrative
Narrative: Teenage voting
Suppose you take a random sample of teenagers aged 18-19, and you find that 53% of the males in your sample are Democrats, and 54% of the females in your sample are Democrats, respectively.
-{Teenage voting narrative} Could these results ever be statistically significant? Why or why not?

Accepted Answer

The answer of For Questions , use the following narrative
Narrative:...

Question 4

If two variables have a statistically significant relationship that does not necessarily mean the two variables have a relationship of practical importance.Describe how this could happen.

Accepted Answer

The answer of If two variables have a statistically significant...

Question 5

Suppose researchers say they 'failed to find a relationship' between two variables that they thought might have been related.What does this say to you, as an educated consumer of statistical information?

Accepted Answer

The study might have been based on a small sample size, which can affect the ability to detect a relationship even if one exists.

Question 6

A minor relationship in the population may achieve __________ significance but fail to achieve __________ significance if there are an extremely large number of observations.

Accepted Answer

The answer of A minor relationship in the population may...

Question 7

Suppose there is not enough evidence to conclude that the relationship in the population is real.Which of the following is not an equivalent way of saying this?

Accepted Answer

"Accepting the null hypothesis" means that there is no evidence of a relationship in the population. However, it does not necessarily imply that the relationship is not statistically significant or that we cannot reject the null hypothesis. Therefore, option C is not an equivalent way of saying there is not enough evidence for the relationship in the population. Options A and B both indicate that we do not have sufficient evidence to reject the null hypothesis, hence they are equivalent ways of saying that the relationship is not real in the population.

Question 8

An interesting relationship in the population may fail to achieve __________ significance if there are too _____ observations.

Accepted Answer

The answer of An interesting relationship in the population may...

Question 9

A __________ test is a statistical procedure that is used to determine whether or not there is a relationship between two categorical variables.

Accepted Answer

The answer of A __________ test is a statistical procedure...

Question 10

A minor relationship that is found to be __________ significant is not necessarily __________ significant.

Accepted Answer

The answer of A minor relationship that is found to...

Question 11

A measure of how unlikely the test statistic would be if the null hypothesis were true is the __________.

Accepted Answer

The answer of A measure of how unlikely the test...

Question 12

Suppose a chi-square test statistic from a sample of size 1,000 is 38.2 with a p-value of .0001, so the relationship is statistically significant.If the sample size for this study had only been based on a sample size of 100 (but the percentages remained the same), what would the chi-square test statistic have been and what conclusion would have been drawn?

Accepted Answer

The chi-square statistic is proportional to the sample size. Reducing the sample size from 1,000 to 100 would reduce the chi-square statistic to 3.82. With this smaller statistic, the p-value would be higher, likely around .052, making the relationship not statistically significant.

Question 13

For Questions , use the following narrative
Narrative: Teenage voting
Suppose you take a random sample of teenagers aged 18-19, and you find that 53% of the males in your sample are Democrats, and 54% of the females in your sample are Democrats, respectively.
-{Teenage voting narrative} Should these results be considered significant from a practical standpoint? Why or why not?

Accepted Answer

The answer of For Questions , use the following narrative
Narrative:...

Quiz 13: Statistical Significance for 2 2 Tables