MATH 218 Midterm Exam, June 24, 1998: Confidence Intervals and Hypothesis Testing, Exams of Mathematics

Download MATH 218 Midterm Exam, June 24, 1998: Confidence Intervals and Hypothesis Testing and more Exams Mathematics in PDF only on Docsity! THIRD MIDTERM, MATH 218 JUNE 24, 1998 Directions. Fill out your name, signature and student ID number on the lines below right now. This is a closed-book exam, but you may use a calculator. Notice that on this exam, all the problems carry equal value. Numerical answers are needed for the problems on this test! USE your calculator! Print your name, handwrite your signature and print your student ID number: Name (printed) Signature (handwritten) Student ID Do not write on this page below this line! 1 (20%) 2 (20%) 3 (20%) 4 (20%) 5 (20%) MATH 218 MIDTERM Problem 1. Auto Motor Company has received a shipment of several thousand parts. A random sample of 81 parts is selected, 8 of which are found to be defective. Find the 90% confidence interval for the true proportion of defects from the entire shipment. MATH 218 MIDTERM Problem 4. Ten smokers are interviewed about the number of cigarettes they smoke each week. The ten answers are 24 51 55 34 56 27 44 43 23 37 Assuming these data come from a normal distribution, find the 95% confidence interval for the unknown mean µ. MATH 218 MIDTERM Problem 5. • Find the 95% confidence interval for the binomial proportion of successes p if a random sample of n = 100 has been selected and the number of successes is 38. • Suppose you want to make sure that p is estimated to within ±0.03. How many more samples must you take from the above population to guarantee this?