QNT 561: Descriptive Statistics and Interpretation

July 14, 2014

Matthew Radio

Descriptive Statistics

Numeric Variable: Willingness to Recommend (collected from customer satisfaction survey)

Distribution is not normally distributed.

See the descriptive statistics in Appendix B and the histogram in Appendix C.

Numeric Variable: Days to Contract Expiration

See the descriptive statistics in Appendix B and the histogram in Appendix C.

Attribute Variable Handset Brands

250 customers who called into the contact center within the last three months were selected at random. 46.8% of the customers own a Samsung brand device, 41.6% own an iPhone, 7.6% own an LG, and 4.0% own a brand under the "Other" category (this includes brands like Palm, Kyoceta, and CellTel). See bar chart in Appendix E. Comment by Matthew Radio: Would a pie chart be more effective?

Descriptive Statistics Interpretation

Willingness to Recommend

250 customers were surveyed at random. The customers were asked how likely they would recommend CellTel to a friend or relative. Customers could select from 1 - 5:

5 = Would Definitely Recommend

4 = Very Likely To Recommend

3 = for Undecided

2 = Not Likely to Recommend

1 = Would Definitely Not Recommend

The average score was 4.37, with a variation of plus or minus 0.16. 71.6% of the responses were scored as a 5 - Would Definitely Recommend. There is a 95% confidence that the population score averages between 4.22 and 4.53. Comment by Matthew Radio: What do you mean by “variation”? Do you mean variance, standard deviation, or some other metric of dispersion?

Days to Contract Expiration

250 customers who called into the contact center within the last three months were selected at random. The average time to contract expiration was 388.68 days, with a variation of plus or minus 30.03 days. One half or more of the customers were above 450 days to their contract expiration. 13.20% of the customers have contracts that have already expired. There is a 95% confidence that the population (CellTel's customer base) average days to contract expiration is between 358.65 and 418.71 days.

APPENDIX A

Raw data used in the analysis

APPENDIX B

Descriptive Statistics Willingness to Recommend and Contract Expiration

Comment by Matthew Radio: What does the “nominal score” mean? Be sure that the meaning of all figures are readily apparent to the reader.

APPENDIX C

Willingness to Recommend and Days to Contract Expiration Histograms

Comment by Matthew Radio: Should each bar be a range and not a single value? If the horizontal scale is continuous, should this be a histogram? (i.e. the bars touch each other)

APPENDIX D

Scatterplot Willingness to Recommend versus Days to Contract Expiration

APPENDIX E

Descriptive Statistics

Attribute Variable Handset Brands