ETS Statistical Analysis 2

Question 1

A researcher finds a correlation of r = 0.85 between two variables. What percentage of variance in the dependent variable is explained by the independent variable?

Accepted Answer

72.25%

Answer

85%

Answer

92.5%

Answer

0.85%

Question 2

In a two-tailed hypothesis test with α = 0.05, what is the critical z-value that defines the rejection regions?

Accepted Answer

±1.960

Answer

±1.645

Answer

±2.326

Answer

±2.576

Question 3

Which measure of central tendency is MOST resistant to extreme outliers?

Accepted Answer

Median

Answer

Mean

Answer

Weighted mean

Answer

Mode

Question 4

A dataset has a mean of 50 and a standard deviation of 10. Using Chebyshev's theorem, at least what percentage of data falls within 3 standard deviations of the mean?

Accepted Answer

88.9%

Answer

75%

Answer

95%

Answer

99.7%

Question 5

In a chi-square goodness-of-fit test, what are the degrees of freedom when testing whether data fits one of 6 categories?

Accepted Answer

5

Answer

4

Answer

6

Answer

7

Question 6

A z-score of −2.0 indicates that a data point is:

Accepted Answer

2 standard deviations below the mean

Answer

2 standard deviations above the mean

Answer

Negative 2 units from the median

Answer

In the 2nd percentile exactly

Question 7

Which type of error occurs when a researcher rejects a true null hypothesis?

Accepted Answer

Type I error

Answer

Type II error

Answer

Power error

Answer

Standard error