Birth weights of male babies at one hospital were recorded for 200 births of boys. A mean of that sample was 35.3 hg and a standard deviation of 7.2 hg. a) Construct a 90% confidence interval for the mean of all boy baby weights. b) A medical Journal claims that the mean weight of male babies is 37.0 hg. Test that claim at a 0.10 level of significance. c) Use a 0.05 level of significance to test a claim that the real standard deviation of boy birth weights is 6.75 hg.
In a recent study of drive-through orders at Burger King, they found out that 365 were accurate and 71 were not accurate. a) Construct a 95% confidence interval for the population percentage of their drive-through order that were not accurate. b) If Burger King claims to have an accuracy of 85% on all drive-through orders, test the claim at the 0.05 levels of significance.