In a recent study on worldhappiness, participants were asked to evaluate their current lives on a scale from 0 to10, where 0 represents the worst possible life and 10 represents the best possible life. The responses were normallydistributed, with a mean of 5.5 and a standard deviation of 2.4. Answer parts (a)-(d) below.

(a) Find the probability that a randomly selected studyparticipant's response was less than 4.

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

(Round to four decimal places asneeded.)

(b) Find the probability that a randomly selected studyparticipant's response was between 4 and 6.

The probability that a randomly selected studyparticipant's response was between 4 and 6 is

(Round to four decimal places asneeded.)

(c) Find the probability that a randomly selected studyparticipant's response was more than 8.

The probability that a randomly selected studyparticipant's response was more than 8 is

(Round to four decimal places asneeded.)

(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.

Theeventsinparts(a),(b),and(c)areunusualbecausealloftheirprobabilitiesare less than 0.05.

C.

The event in part (a) is unusual because its probability is less than 0.05.