2. Let sample proportion . How large a sample should be taken to be 95 % sure that the error of estimation does not exceed 0.02 when estimating a proportion? 3. A business consultant wanted to...

Extracted text: 2. Let sample proportion . How large a sample should be taken to be 95 % sure that the error of estimation does not exceed 0.02 when estimating a proportion? 3. A business consultant wanted to investigate if providing day care facilities on premises by companies reduces the absentee rate of working mothers from companies that provide day care facilities on premises. Sample of 50 mothers selected from the companies that provide day care facilities was taken. These mothers missed an average of 6.4 days from work last year with a standard deviation of 1.20 days. Another sample of 50 such mothers taken from companies that do not provide day care facilities on premises showed that these mothers missed an average of 9.3 days last year with a standard deviation of 1.83 days. Construct a 98 % confidence interval for the difference between the two population means. 4. Assume that 66 % of single women and 81.9 % of single men own cars. Also assume that these estimates are based on random samples of 1640 single women and 1800 single men. Develop a 99 % confidenee interval for the difference between the two population proportions. Page 1 I 1 Q