Bluebook SAT Test SAT Data Analysis & Statistics 1

Question 1

A researcher records the test scores of 30 students: the mean score is 74 and the median score is 81. What does this relationship between mean and median suggest about the distribution of scores?

Accepted Answer

The distribution is skewed left, pulled down by a few very low scores

Answer

The distribution is symmetric around 77.5

Answer

The distribution is skewed right, pulled up by a few very high scores

Answer

The mean and median are too close to draw any conclusions

Question 2

A scatterplot of hours studied (x) vs. exam score (y) shows a strong positive linear association with r = 0.91. A student concludes that studying more causes higher scores. Which statement best evaluates this conclusion?

Accepted Answer

The conclusion is not valid; correlation does not establish causation

Answer

The conclusion is valid because r = 0.91 is close to 1

Answer

The conclusion is valid because the association is linear

Answer

The conclusion is not valid because r must equal 1.0 to support any claim

Question 3

The table below shows two data sets, each with 5 values:
Set A: 10, 10, 10, 10, 10
Set B: 6, 8, 10, 12, 14
Which correctly compares their standard deviations?

Accepted Answer

Set B has a larger standard deviation than Set A

Answer

Set A has a larger standard deviation than Set B

Answer

Both sets have the same standard deviation because they have the same mean

Answer

Standard deviation cannot be determined without a larger sample

Question 4

A polling organization surveys 500 randomly selected voters and reports that 54% support a ballot measure, with a margin of error of ±3 percentage points. What is the best interpretation of this result?

Accepted Answer

It is plausible that the true population support is between 51% and 57%

Answer

Exactly 54% of all voters support the measure

Answer

The true population percentage is guaranteed to be between 51% and 57%

Answer

The poll is unreliable because it did not survey all voters

Question 5

A data set of 9 values has a median of 45. If the largest value in the set is increased from 90 to 200, what happens to the median and mean?

Accepted Answer

The median stays the same; the mean increases

Answer

Both the median and mean increase

Answer

The median increases; the mean stays the same

Answer

Both the median and mean stay the same

Question 6

Two classes each take the same 100-point exam. Class 1 has a mean of 78 and a standard deviation of 4. Class 2 has a mean of 78 and a standard deviation of 14. Which statement is most accurate?

Accepted Answer

Both classes performed equally overall, but Class 2's scores are more spread out

Answer

Class 1 performed better overall because its scores are more consistent

Answer

Class 2 performed better overall because it has more variability

Answer

Class 1's scores are more spread out around the mean than Class 2's scores