Question

7.2.9-T Question Help Here are summary statistics for randomly selected weights of newborn girls: n=152 x 30.5 ha, s. 79 hg. Construct a confidence interval estimate of the mean Use a 95% confidence level. Are these results very different from the confidence interval 28.7 hg <<32.9 hg with only 14 sample values, x = 30.8 hg, and s. 37 hg? What is the confidence interval for the population mean ? ng<< ng (Round to one decimal place as needed)

Answer 1

Solution - n = 152, X = 30.5 kg S= 7.9 kg To construct 95% confidence interval, we need , & deque of freedom - n1 = 152-1 =151 * value of talent where a . is fucom 100(1-2).2.confidence A

interval. So for 95% confidence x = 0.05 and a = 0.025 from t-table, value of 140.025, 151 5 1984 mean lor → confidence interval of 95% for [x - tal = h = (x + tola in ] (30.5=1-484* ] <<fo=#1.947 < 29.2 - lu 31.8.

So 95% confidence tion mean is - level for popula- | 29.2 hg < 4 < 3108 hy Yes! The result is very different from sample of 14, because as the sample size increase interval converges to mean value more and more..