Inferential Statistics
Grape, Inc’s uDevice X and uDevice X Plus’s daily sales for the year 2014 are reproduced in Appendix C. The monthly sales figures are as shown in table 1.
The descriptive statistics for the data in Appendix C is shown in table 2 as extracted from Grape, Inc.xls, Sheet uDevice X – uDevice X Plus D20
Test of Significance between uDevice X and uDevice X plus Sales
In order to test whether there is a statistically significant difference between uDevice X and uDevice X Plus, student t-test for two independent samples was used. It was assumed that the same have an equal variance and mean, since Grape, Inc. customers have relatively similar demographic and consumption characteristics. In addition, initial descriptive statistics revealed that the data in Appendix C is normally distributed. In order to test the difference in market shares between uDevice X and uDevice X Plus
and further assuming that Mean of uDevice X=µ1
and Mean of uDevice X Plus=µ2 then
Null Hypotheis assumes that the difference between µ1 and µ2 is 0 that
H0: µ1=µ2s
H1:µ≠µ2
T-test Results at 5% significance level are as shown in table 3
Both a two-tailed and one-tailed t-test show a statistically significant difference between the means of the respective device sales, showing that uDevice X plus has a larger market share in the United States compared to uDevice X.
References
Creswell, J. (1998). Qualitative inquiry and research design: Choosing among five traditions. Thousand Oaks: Sage Publications.
Wilson, E. (2012). School-based Research: A Guide for Education Students. London: SAGE Publications Ltd.
Appendix A
Annual Sales Histogram & Scatter Plot
Raw Daily uDevice X and uDevice X plus Sales
