DSAT Data Analysis 3

Question 1

Of 80 students who play sports, 60 get good grades. Of 120 who don't play sports, 40 get good grades. What fraction of all 200 students get good grades?

Accepted Answer

1/2

Answer

Total with good grades = 60 + 40 = 100 out of 200 students = 100/200 = 1/2.

Question 2

A city's population was 50,000 in 2000 and 80,000 in 2020. What was the percent increase over this period?

Accepted Answer

60%

Answer

Percent increase = (80,000 − 50,000)/50,000 × 100 = 30,000/50,000 × 100 = 60%.

Question 3

A random sample of 500 voters shows 55% support a ballot measure, but the true population support is 52%. What best explains the 3-point difference?

Accepted Answer

The difference is due to sampling variability

Answer

Random samples naturally vary from the true population value; this difference is expected sampling variability.

Question 4

Annual sales (in millions) over four years: $4M, $6M, $5M, $8M. What is the mean annual sales?

Accepted Answer

$5.75M

Answer

Mean = (4 + 6 + 5 + 8) / 4 = 23 / 4 = $5.75M.

Question 5

A study reports a drug reduces cholesterol by an average of 15 points with a p-value of 0.03. Which conclusion is most appropriate?

Accepted Answer

The result is statistically significant at the 0.05 level

Answer

A p-value of 0.03 is less than 0.05, so the result is statistically significant at the 5% significance level.

(DSAT) Digital SAT Practice Test

(DSAT) Digital SAT Practice Test

DSAT Data Analysis 3