In a recent study on world happiness, participants were asked to evaluate their current lives on a scale from 0 to 10, where 0 represents the worst possible life and 10 represents the best possible life. The responses were normally distributed, with a mean of

5.9

and a standard deviation of

2.5.

Answer parts

(a)-(d)

below.

Question content area bottom

Part 1

(a) Find the probability that a randomly selected study participant's response was less than

4.

The probability that a randomly selected study participant's response was less than 4 is

enter your response here.

(Round to four decimal places as needed.)

Part 2

(b) Find the probability that a randomly selected study participant's response was between

4

and

6.

The probability that a randomly selected study participant's response was between

4

and

6

is

enter your response here.

(Round to four decimal places as needed.)

Part 3

(c) Find the probability that a randomly selected study participant's response was more than

8.

The probability that a randomly selected study participant's response was more than

8

is

enter your response here.

(Round to four decimal places as needed.)

Part 4

(d) Identify any unusual events. Explain your reasoning. Choose the correct answer below.

A.

The events in parts

(a)and(c)

are unusual because their probabilities are less than 0.05.

B.

The event in part

(a)

is unusual because its probability is less than 0.05.

C.

Theeventsinparts(a),(b),and(c)areunusualbecausealloftheirprobabilitiesare

less

than 0.05.

D.

Therearenounusualeventsbecausealltheprobabilitiesaregreater

than 0.05.