1) A car producer claims a certain type of car is fuel-saving and can be driven 25 miles/gallon and a st dev of 2.8 miles/gallon. An analyst wants to test this claim and wants a 1% risk of concluding the statement is false when it in fact is true. He chooses 30 observations. Calculate the probability for type 2 error if the true mean is 24? I tried: X-bar critical = 26.32 and 23.68 and got P(-0.62 < Z < 4.53) = F(0.62) But the book's answer is 0.64? 2) A company considers launching a new product if the proportion of customers who will buy it is at least 0.2. A sample of 100 was taken. The null hypothesis (P =0.2) is rejected if the smaple proprtion is at least o.27. The following requirements must be met: P(not rejecting H0) = at least 99% if true proportion is 0.17 P(rejecting H0) = at least 99% if true proportion is 0.27 e) What sample size is required (at least)? Book: 365 f) What is the significance level? Book: 17% How do you solve this??