Stat 351 Homework #6. Due date: Tuesday July 28, 2020 at 05.00 p.m. CDT. Submit your homework via one of the following methods. 1. Type your answers in a word document and submit as a word document...

Solutions for number 2 only


Stat 351 Homework #6. Due date: Tuesday July 28, 2020 at 05.00 p.m. CDT. Submit your homework via one of the following methods. 1. Type your answers in a word document and submit as a word document file or pdf file. 2. Write down your answers in separate sheets of paper and submit the scan copy of the answer. 3. Write down your answers in separate sheets of paper and submit snapshot of the answer. This question is based on Section 19.1-19.2 Statistical Methods for Quality Control part. 1. A production process that is in control has a mean (µ) of 16 and a standard deviation (σ) of 0.5. Sample of size 25 is used for the inspection process. a) Determine the lower control limit. Show your work for full credit. b) Determine the center line/limit. c) Determine the upper control limit. Show your work for full credit. This question is based on Section 12.2 Test of independence. 2. The National Sleep Foundation used a survey to determine whether hours of sleep per night are independent of age (Newsweek, January 19, 2004). A sample of individuals was asked to indicate the number of hours of sleep per night with categorical options: fewer than 6 hours, 6 to 6.9 hours, 7 to 7.9 hours, and 8 hours or more. Later in the survey, the individuals were asked to indicate their age with categorical options: age 39 or younger and age 40 or older. Sample data follow. a) State the null and alternative hypotheses. b) Calculate the expected frequency. Show your work for full credit. c) Find the degrees of freedom. Show your work for full credit. d) Compute chi-square statistic (?2). Show your work for full credit. e) Draw your conclusion. State your conclusion in a complete sentence and use words a non-statistician would understand. Show your work for full credit. Hours of Sleep 39 or younger 40 or older Fewer than 6 36 33 6 to 6.9 58 54 7 to 7.9 75 72 8 or more 63 90