Statistics

Statistics

4. The probability that 0, 1, 2, 3, or 4 people will be placed on hold when they call a radio talk show is shown in the distribution. Find the mean, variance, and standard deviation for the data. The radio station has four phone lines. Remember: μ=E(x)=∑ ▒ 〖 xP(x) 〗

0

1

2

3

4

( )

0.18

0.34

0.23

0.21

0.04

5. If a student randomly guesses at five multiple choice questions, find the probability that the student gets exactly three correct. Each question has five possible choices. *Hint: = 5, = 3 , and = 1 5 + use the binomial

6. A coin is tossed four times. Find the mean, variance, and standard deviation of the number of heads that will be obtained.

1 2

1 2

= 4, =

, =

a. Mean:

b. Variance:

c. Standard deviation:

Answer key is found on page 86.

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