D E A Tax Prep Time (hrs) B C 35.3 30.5 37.4 Interval Estimate of a Population Mean: Sigma Known Case Sample Size 26.5 Sample Mean 13 49.9 28.8 44 61.6 0.5 Population Standard Deviation Confidence Coefficient Level of Significance Margin of Error 40.5 34.9 47.9 Point Estimate C.I. Lower Limit 36.6 C.I. Upper Limit 24.1 39.8 Data range A:A 47.8 18.5 36.6 39.2 14.5 37.3 40.5 49.3 45.5 7 28.3 B 19.5 9 5.6 0 52.6 -1 41.4 32 45.3 33 39 34 33.7 35 29.4 36 14.5 37 40.1 38 33.7 39 36.9 40 5.6 41 33.7 F Formulas Used #N/A #N/A 10 0.95 #N/A #N/A #N/A #N/A #N/A G