Take this Quiz: SAT Math — probability, and what a sample is allowed to say | Zestly

Question 1

A survey of 200 employees at a firm found that 80 prefer working from home, 70 prefer the office, and 50 have no preference. If one employee is chosen at random from the whole group, what is the probability that the employee prefers working from home?

Accepted Answer

$2/5$

Answer

$8/15$

Answer

$1/4$

Answer

$4/7$

Question 2

In a study of 150 students, 60 are in the drama club and 90 are not. Among the drama club members, 40 like jazz. Among those not in the club, 30 like jazz. If one student is chosen at random from the drama club, what is the probability that this student likes jazz?

Accepted Answer

$2/3$

Answer

$7/15$

Answer

$4/15$

Answer

$1/3$

Question 3

A survey of 300 residents found that 120 support a new park and 180 do not. Of those who support it, 50 are under thirty years old. Of those who do not support it, 70 are under thirty. If one resident is chosen at random from among those under thirty, what is the probability that this resident supports the park?

Accepted Answer

$5/12$

Answer

$1/6$

Answer

$7/12$

Answer

$2/5$

Question 4

A bag holds 12 red marbles, 8 blue marbles and 5 green marbles. One marble is drawn at random. What is the probability that it is NOT blue?

Answer

$8/25$

Answer

$2/5$

Answer

$13/25$

Answer

$17/25$

Question 5

A box holds 20 pens, of which 4 are defective. One pen is taken at random. What is the probability that it is defective?

Answer

$1/4$

Answer

$1/5$

Answer

$4/5$

Answer

$1/20$

Question 6

A researcher randomly selects 50 students from a high school of 1000 and finds that 30 of them prefer online learning. Based on this sample, what is the best estimate of the number of students in the whole school who prefer online learning?

Answer

$600$

Answer

$1000$

Answer

$30$

Answer

$500$