ACT Math — Statistics and Probability — Drill 3

About This Drill

ACT Math — Statistics and Probability — Drill 3 is a Math practice drill covering Statistics and Probability. It contains 5 original questions created by Brian Stewart, a Barron's test prep author with over 20 years of tutoring experience.

This ACT Statistics and Probability drill covers reading and interpreting frequency tables, calculating weighted averages from grouped data, applying geometric probability, computing probability without replacement, and analyzing the shape, center, and spread of a data distribution.

Questions in This Drill

1. The frequency table below shows the number of hours per week that 30 students spend studying.
   Hours per week    Students
   0 – 2                   4
   3 – 5                   9
   6 – 8                  11
   9 – 11                  6
   What fraction of students study 6 or more hours per week?
2. In a class, the final grade is computed as follows: homework counts 20%, quizzes count 30%, and the final exam counts 50%. A student earns an 80 on homework, a 70 on quizzes, and a 90 on the final exam. What is the student's final grade?
3. A square dartboard has a side length of 20 inches. A circular target is painted in the center of the board with a radius of 5 inches. Assuming a dart lands at a uniformly random point on the board, what is the probability that it lands inside the circular target? (Use π ≈ 3.14)
4. A drawer contains 6 black socks and 4 white socks. Two socks are drawn one at a time without replacement. What is the probability that both socks are black?
5. A teacher records scores on a 50-point quiz for 20 students. The scores are summarized below.
   Score Range    Students
   10 – 19                1
   20 – 29                2
   30 – 39                5
   40 – 49                9
   50                      3
   Which of the following best describes this distribution?