FREE SAT Command of Evidence (Quantitative) Questions and Answers 3

Question 1

A researcher studies the relationship between hours of sleep and test scores. The scatter plot shows a correlation coefficient of r = 0.73. Which statement best describes this relationship?

Accepted Answer

There is a strong positive correlation between sleep and test scores

Answer

There is a weak negative correlation between sleep and test scores

Answer

There is no significant correlation between sleep and test scores

Answer

The correlation is moderate but the direction cannot be determined

Question 2

A survey of 500 students shows that 60% prefer online learning. The margin of error is ±4%. Which conclusion is most appropriate?

Accepted Answer

Between 56% and 64% of all students likely prefer online learning

Answer

Exactly 60% of all students prefer online learning

Answer

At least 64% of all students prefer online learning

Answer

The survey is too small to draw any conclusions

Question 3

Which of the following scenarios would most likely produce a biased sample when studying average income in a city?

Accepted Answer

Surveying people at luxury shopping malls only

Answer

Randomly selecting households from the phone directory

Answer

Using stratified sampling by neighborhood

Answer

Conducting online surveys with random invitations

Question 4

A study finds that students who eat breakfast score 15 points higher on average than those who don't. What additional information is most needed to evaluate this finding?

Accepted Answer

The standard deviation of the scores and sample sizes

Answer

The names of the schools involved in the study

Answer

The specific breakfast foods consumed

Answer

The time of day the tests were administered

Question 5

A line of best fit for data comparing study time (x) and test scores (y) has the equation y = 2.5x + 65. What does the y-intercept represent in this context?

Accepted Answer

The predicted test score for a student who studies 0 hours

Answer

The average test score for all students

Answer

The increase in test score for each additional hour studied

Answer

The maximum possible test score

Question 6

Two groups of 100 students each take different versions of a test. Group A has a mean of 78 with standard deviation 12. Group B has a mean of 82 with standard deviation 8. Which statement is most accurate?

Accepted Answer

Group B performed better and more consistently than Group A

Answer

Group A has more reliable results because of the larger standard deviation

Answer

Both groups performed equally well overall

Answer

Group A's results are more spread out, making them more representative