Chapter 16 Quiz Review

Correlations are best suited for ____ data.

• Discrete

• Continuous

Tags

CCSS.HSS.ID.C.9

What do we call our x-axis in dealing with correlations?

• Predictor

• Criterion

• Factor

• Level

Answer explanation

The predictor variable is similar to an independent variable. You think it's the best explanation of your outcome.

Tags

CCSS.HSS.ID.B.6A

Which of the following contains the strongest correlation?

• r = -.61

• r = .88

• r = -.91

• r = .34

Tags

CCSS.HSS.ID.B.5

Which of the following best describes the correlation depicted to the left?

• The graph has a weak relationship.

• The graph contains no correlation.

• The graph has a positive correlation.

• The graph has a curvilinear relationship.

Tags

CCSS.HSS.ID.B.5

A researcher obtains a correlation of r = -.41 for a sample of n = 25 individuals. What is the critical value, and what must we do with our null?

• r = .396; Fail to reject the null

• r = .388; Reject the null

• r = .337; Reject the null

• r = .381; Fail to reject the null

Answer explanation

Assuming that this is a nondirectional test with α = .05, we can see that a sample of n = 25 equates to a df of 23 (25 - 2 = 23). Now, we must use our new r-table to find the corresponding r critical value which ends up being r = .396. Since r = -.41 doesn't exceed .396, we must fail to reject the null.

As the sample size gets smaller, what happens to the magnitude of the correlation necessary for significance?

• It gets larger

• It gets smaller

• It remains unaffected

• It influences our effect size

Answer explanation

With a small sample, it is easy to get a relatively good correlation just by chance. Therefore, a small sample requires a very large correlation before you can be confident that there is a real (nonzero) relationship in the population.

Tags

CCSS.HSS.ID.B.6B

Which of the following would more than likely give you a negative correlation?

• Height and weight for a group of adults

• Daily high temperature and daily energy consumption for the summer

• SAT scores and college achievement

• Daily high temperature and daily energy consumption for the winter

Answer explanation

Negative: Higher temperature tends to decrease the need for heating, making this a likely negative correlation.

Tags

CCSS.HSS.ID.B.5

The data points would be clustered more closely around a straight line for a correlation of -.80 than for a correlation of +.55.

• True

• False

Answer explanation

True. Recall, the numerical value indicates the strength of the relationship. The sign only indicates the direction.

Tags

CCSS.HSS.ID.C.8

A correlation can never be greater than +1.00.

• True

• False

Tags

CCSS.HSS.ID.B.5

How would we classify a correlation that has a value of r = .68?

• Weak

• Strong

• Moderate

• No correlation

Tags

CCSS.HSS.ID.B.5