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

5.6

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 event in part

(a)

is unusual because its probability is less than 0.05.

B.

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

less

than 0.05.

C.

The events in parts

(a)and(c)

are unusual because their probabilities are less than 0.05.

D.

Therearenounusualeventsbecausealltheprobabilitiesaregreater