Answer Happy

Read and understand carefully each problem situation. Solve each problem situation. Show complete solutions. 1. You want to find the average shirt size for people in a certain city so that you can make a supply with little waste. To do this you obtained a sample of 20 people and their shirt sizes: 18 22 17 19 19 20 19.5 22 20 22 CH 17.5 19 21 20 Chain 1 237 seconds 35 seconds 23 20.5 Obtain a 90% confidence interval of the population mean. 2. A study of 87 randomly selected companies with a telemarketing operation revealed that 39% of the sampled companies used telemarketing to assist them in order processing. Estimate and interpret population proportion of telemarketing companies at 95% confidence level that use their telemarketing operation to assist them in order processing. - Test 1 3. A fast food researcher wants to see whether Food Chain 1 or Food Chain 2 serves their customers faster (food chains). To do this, he recorded the time between when an order is taken and when it is served. He took a random sample of 60 orders from the two fast food chains. With the following results: 21 19 18.5 21 Chain 2 254 seconds 21 seconds Sample Mean Sample Standard Deviation Construct a 95% confidence interval for the true mean difference between the two average serving times. 4. Two exams were conducted among two sets of people to evaluate the difficulty of the exams. There were 50 people who took Test 1 and 60 people who took Test 2. Thirty-five people passed the first exam while 47 passed the second exam. Construct a 99% confidence interval for the true difference between the two population proportions. [Be guided of the table below to record the data available.] Test 2