(Solved): 4. Using Excel - Constructing an interval estimate for a population proportion Suppose Frank wants ...

4. Using Excel - Constructing an interval estimate for a population proportion Suppose Frank wants to know what proportion of students at his university prefers dogs to cats. He polled a random sample of 60 students and asked hall of them, "Cats or dogs?" He asked the other half, "Dogs or cats?" To answer the questions that follow, download an Excelf spreadsheet that contains the hypothetical resuits of Frank's study by clicking on the following words in bold: Download Excel File. The value "cats" indicates the respondent preferred cats; the value "dogs" indicates the respondent preferred dogs. In the following sample. Excel spreadsheet, enter the appropriate formulas to construct an interval estimate of the population proportion of students at the university who prefers dog5, Note that only the first 18 rows are shown here, but all 60 values are included in the downloaded Excel page. Use a $90\%$ confidence level. (Note: The Excel 2010 functions NORM.S.INV and NORM. INV are equivalent to previous versions of Excel's functions NORMSINV and NORMINV.) Enter these same formulas in your downloaded Excel spreadsheet. Use the calculated values to complete the following statement: The number of students in the sample who prefer doys is can say with $90\%$ confidence that between The point estimate for the population proportion is Using percentages, Frank and of students at his unuversity prefers dogs: