Worksheet Activity I

Exercise I

Open the Excel workbook in Exe 8.1B.xlsx from the Exercises folder. Obtain the sample size, sample mean weight loss and the sample standard deviation of the weight loss for Diet B. Place these results in the block of cells F23 to F25, using the same format as that employed for the Diet A results in the above example.

Briefly interpret your findings. What do these results tell you about the relative effectiveness of the two weight-reducing diets?

The mean is 3.710 and the standard deviation is 2.769. This indicates that diet A is more effective than B.

Exercise II

Open the Excel workbook in Exe 8.2B.xlsx from the Exercises folder. Obtain the sample median, first and third quartiles and the sample interquartile range of the weight loss for Diet B. Place these results in the block of cells F26 to F29, using the same format as that employed for the Diet A results in the above example.

Briefly interpret your findings. What do these results tell you about the relative effectiveness of the two weight-reducing diets?

The median is 3.745 and IQR = 3.532. Despite its effectiveness, diet B is less effective compared to diet A.

Exercise III

Open the Excel workbook in Exe 8.3D.xlsx from the Exercises folder. Obtain the frequencies and percentage frequencies of the variable Brand, but this time for the Area 2 respondents, using the same format as that employed for the Area1 results in the above example.

Briefly interpret your findings. What do these results tell you about the patterns of brand preferences for each of the two demographic areas?

In Area 2, 33.3% preferred brand B, 21,1% preferred brand A, and the remaining 45,5% preferred other brand.