Texting:Five teenagers are selected at random. LetX

be the number of them who have sent text messages on their cell phones within the past30

days. According to a recent study, the probability distribution ofX

is as follows:

x

0

1

2

3

4

5

P

x

0.014

0.098

0.258

0.343

0.227

0.060

Send data to Excel

Part 1 of 6

(a) FindP

4

.

=

P

4

0.227

.

Part 2 of 6

(b) FindP

More than3

.

P

More than=

3

0.287

.

Part 3 of 6

(c) Find the probability that four or more of the teenagers sent text messages.

The probability that four or more of the teenagers sent text messages is0.287

.

Part 4 of 6

(d) Find the probability that fewer than two of the teenagers sent text messages.

The probability that fewer than two of the teenagers sent text messages is0.112

.

Part:4 / 6

4 of 6 Parts Complete

Part 5 of 6

(e) Compute the mean

X

. Round the answer to two decimal places.

=

X

2.85

.

Part:5 / 6

5 of 6 Parts Complete

Part 6 of 6

(f) Compute the standard deviation

X

. Round the answer to three decimal places.

=

X

.