Question

A cellular phone service provider is offering a new calling plan that it claims will result in an average savings of more than 20% for its customers who switch to the plan. To evaluate this claim, a consumer watchdog organization contacted a random sample of this provider's customers who enrolled in the new plan and computed their individual savings (as a percentage of their original monthly bill).

PctSavings(%)

33.17

21.43

19.29

24.59

29.25

24.09

21.36

14.27

26.29

16.85

19.09

27.56

25.65

15.02

18.53

17.06

21.16

1. Use Minitab to construct a normal probability plot to check the normality condition. Report the value of the Anderson-Darling statistic (AD) below.

AD = (rounded to 3 decimal places; 2 for Minitab
Express)

2. Use Minitab to conduct a test to see if there is enough
evidence for the provider's claim. Report the value of the
appropriate test statistic and the p-value.

Test Statistic Value =? (rounded to 2 decimal places)

p-value =? (rounded to 3 decimal places; 4 for Minitab Express)

Answer #1

1)

AD = 0.2

p-value = 0.861 > 0.05

hence normality assumption is valid

2)

One-Sample T: PctSavings

Test of μ = 20 vs > 20

Variable N Mean StDev SE
Mean 95% Lower Bound
T P

PctSavings 17
22.04 5.24
1.27 19.82
1.60 0.064

TS = 1.60

p-value = 0.064 > 0.05

hence we fail to reject the null hypothesis

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 1 minute ago

asked 5 minutes ago

asked 7 minutes ago

asked 8 minutes ago

asked 30 minutes ago

asked 32 minutes ago

asked 39 minutes ago

asked 43 minutes ago

asked 55 minutes ago

asked 55 minutes ago

asked 58 minutes ago

asked 1 hour ago