10th grade statistics and probability

Question 1

Find the population standard deviation of: 7, 11

Answer 

Question 2

Survey: Likes science & is in Club — 7; Likes science & not in Club — 23; Doesn't like science & in Club — 24; neither — 10. Given a student is in the Club, what is the probability they like science? Simplest form.

Answer (as a fraction)

Question 3

P(A) = 0.6, P(B) = 0.3 and P(A and B) = 0.2. Find P(A or B).

Answer 

Question 4

A box has 3 vanilla and 3 chocolate biscuits. Two are eaten at random. Find P(at least one chocolate) as a fraction in simplest form.

Answer (as a fraction)

Question 5

Estimate the mean from this grouped table: 0–10: 6, 10–20: 1, 20–30: 9, 30–40: 4. Round to 1 decimal place.

Answer 

Question 6

A bag has 2 red and 7 blue counters. Two are taken out without replacement. Find P(both red) as a fraction in simplest form.

Answer (as a fraction)

Question 7

In a class, P(plays sport) = 0.3, P(plays an instrument) = 0.3 and P(sport or instrument) = 0.5. Find P(sport and instrument).

Answer 

Question 8

In a histogram, a bar covers a class of width 20 and has frequency density 2. What is the frequency?

Answer 

Question 9

Set X: 46, 49, 52, 55, 58 Set Y: 34, 43, 52, 61, 70 Both have mean 52. Which set has the larger standard deviation?

• A. X
• B. Y
• C. They are equal

Question 10

Some lengths have standard deviation 6 cm. Every length is multiplied by 5. What is the new standard deviation, in cm?

Answer 

Question 11

P(A) = 0.5, P(B) = 0.2 and P(A and B) = 0.1. Are A and B independent?

• A. Yes
• B. No

Question 12

Set A: 3, 8, 11, 14, 19. Set B: 10, 11, 11, 12, 11. Which set has the larger standard deviation?

• A. A
• B. B
• C. They are equal

Question 13

A card is drawn from a standard 52-card deck. Find the probability that it is a king or a heart. Give a fraction in simplest form.

Answer (as a fraction)

Question 14

A playlist has 2 pop songs and 8 rock songs. Two different songs are picked at random. Find P(one of each type) as a fraction in simplest form.

Answer (as a fraction)

Question 15

Find the population standard deviation of: 11, 13, 11, 13

Answer 

Question 16

Survey: Likes science & is in Club — 21; Likes science & not in Club — 8; Doesn't like science & in Club — 20; neither — 19. Given a student is in the Club, what is the probability they like science? Simplest form.

Answer (as a fraction)