Question

The relative frequency distribution of the number of phobias reported by a hypothetical sample of 500 college students is given as follows.

0–2 0.48
3–5 0.26
6–8 0.12
9–11 0.09
12–14 0.05

Required:
a. What is the probability that a college student expresses fewer than three phobias?
b. What is the probability that a college student expresses more than eight phobias?
c. What is the probability that a college student has between 3 and 11 phobias?

Answer 1

a. 0.48

b. 0.14

c. 0.47

Explanation:

Data provided in the question

0 - 2 0.48

3 - 5 0.26

6 - 8 0.12

9- 11 0.09

12- 14 0.05

Based on the above information

a. The probability for fewer than three phobias is

= P( x < 3)

= 0.48

b. The probability for more than eight phobias is

= P( x >8)

= 0.09 + 0.05

= 0.14

c. Probability between 3 and 11 phobias is

= P(3 < x < 11)

= 0.26 + 0.12 + 0.09

= 0.47