Business-decision Making

TO : Piggybank Product Development Team

FROM : Researcher

DATE : June 11 2007

SUBJECT : Determination of Sample Mean

Through Appropriate Statistical Research Analysis , the required number of cardholders that should be sampled is 13530 . This figure is in line with the data that was previously provided as follows

Sampling error 10

Population Standard Deviation 500

Confidence Interval : 98

It was earlier signified that the company is only willing to spend 10 ,000 .00 for the sampling purposes . However , if the cost of sampling is 5 per cardholder , it would mean that

only 2000 cardholders can be sampled for the study

If the number of samples at 13350 will not be met , there might be a problem in terms of the upcoming analysis in getting the true condition of the data collected . The sampling error of 10 will not be a valid clause to determine any significant analysis for , this aspect measures the differences in mean and standard deviation for a specified number of samples (Wikipedia , 2007

The confidence interval is the range of values which is likely to include a specific population parameter of a given set of data (Easton McColl . Thus , if the inappropriate number of the population sample is not used , there will be some discrepancies between the estimated statistical analysis and the true representation of the data collected

Number of cardholders to be sampled Data

Population Standard Deviation 500

Sampling Error 10

Confidence Level 98 Intemediate Calculations

Z Value -2 .326347

Calculated Sample Size 13529 .72591 Result

Sample Size Needed 13530 References

Easton , V , McColl , J . Confidence Intervals . Lancaster University Statistics Glossary . Retrieved June 10 , 2007 from HYPERLINK "http /www .cas .lancs .ac .uk /glossary_v1 .1 /confint .html confinterval http /www .cas .lancs .ac .uk /glossary_v1 .1 /confint .html confinterval

Wikipedia . 2007 . Smapling Error . Wikipedia , the free encyclopedia Retireved June 10 , 2007 from HYPERLINK "http /en .wikipedia .org /wiki /Sampling_error http /en .wikipedia .org /wiki /Sampling_error...