Final Exam Review Probability Worksheet With Answers (Page 5 of 10) in pdf

Final Exam Review Probability Worksheet With Answers Page 5

37) A random sample of 10 parking meters in a beach community showed the following incomes for a day. Assume

the incomes are normally distributed.

$3.60 $4.50 $2.80 $6.30 $2.60 $5.20 $6.75 $4.25 $8.00 $3.00

Find the 95% confidence interval for the true mean.

Answer: ($3.39, $6.01)

38) The grade point averages for 10 randomly selected high school students are listed below. Assume the grade

point averages are normally distributed.

2.0 3.2 1.8 2.9 0.9 4.0 3.3 2.9 3.6 0.8

Find a 98% confidence interval for the true mean.

Answer: (1.55, 3.53)

39) Suppose you are using

= 0.05 to test the claim that µ 32 using a P-value. You are given the sample statistics

n = 35, x = 31.1, and

= 2.7. Find the P-value.

Answer: 0.0448

40) Given H 0 : µ = 25, H 1 : µ 25, and P = 0.028. Do you reject or fail to reject H 0 at the 0.01 level of significance?

Answer: fail to reject H 0

41) Given H 0 : µ 18, H 1 : µ < 18, and P = 0.068. Do you reject or fail to reject H 0 at the 0.05 level of significance?

Answer: fail to reject H 0

42) A local school district claims that the number of school days missed by its teachers due to illness is below the

national average of 5. A random sample of 40 teachers provided the data below. At

= 0.05, test the district's

claim using P-values.

0 3 6 3 3 5 4 1 3 5

7 3 1 2 3 3 2 4 1 6

2 5 2 8 3 1 2 5 4 1

1 1 2 1 5 7 5 4 9 3

Answer: P-value = 0.000001, P < , reject H 0 ; There is sufficient evidence to support the school district's claim.

Final Exam Review Probability Worksheet With Answers Page 5