Question

Is there a difference in the variance of the satisfaction rating of traditional cellphone provider who bill for service at the end of a month (often under a contract) and prepaid cellphone service providers who bill in advance without a contract? The file CellphoneProviders (see folder) contains the satisfaction rating for 10 traditional cellphone providers and 13 prepaid cellphone service. A. At the 0.05 level of significance, is there evidence of a difference in the variability of the satisfaction rating between the types of cellphone providers? B. Determine the p-value in (A) and interpret its meaning.

CellPhone Provider	Type	Rating
Consumer Cellular	Traditional	89
Ting	Traditional	88
Grat Cell/Jitterbug	Traditional	79
Credo Mobile	Traditional	78
Virgin Mobile	Traditional	76
U. S. Cellular	Traditional	73
T-Mobile	Traditional	73
Verizon Wireless	Traditional	70
AT&T	Traditional	68
Sprint	Traditional	67
Republic Wireless	PrePaid	87
Cricket	PrePaid	85
Page Plus Cellular	PrePaid	84
Straight Talk	PrePaid	80
TracFone	PrePaid	79
MetroPCS	PrePaid	78
Virgin Mobile	PrePaid	76
Net10	PrePaid	76
Boost Mobile	PrePaid	75
T-Mobile	PrePaid	74
Verizon Wireless	PrePaid	70
AT&T	PrePaid	70
Sprint	PrePaid	66

PLEASE SOLVE IT ON EXCEL. STEP BY STEP THANK YOU

Answer 1

Answer(A):

To test the difference in the variability of the satisfaction rating between the types of cellphone providers, we need to run the F test for two sample variances. In Excel, we can do it as below:

1. Copy the data in Excel.

2. Go to the data

3. open the data analysis toolpack

4. select the data for both variables(shown in screen shot)

The output of F test is as below:

F-Test Two-Sample for Variances
	Variable 1	Variable 2
Mean	76.1	76.9231
Variance	58.3222	38.4103
Observations	10	13
df	9	12
F	1.5184
P(F<=f) one-tail	0.2457
F Critical one-tail	2.7964

Answer(B):

the p-value of the test is 0.2457 which is greater than 0.05 and it suggest that the F test is not significant and we can conclude that there is no difference in the variability of the satisfaction rating between the types of cellphone providers.