Just Statistics ((Minitab)) Expert !!

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DSCI 346-01 F16: Chapter 15 On-Paper Assignments 30 points: each question = 15 points

Begin by re-writing the problem. Minitab is required; attach or include your output. Use Word; you may handwrite equations. You may want to refer to the Minitab handout for Chapter 15 which can be found on Canvas under Chapter 15 Minitab Handouts under Modules.

1. High levels of cockpit noise in an aircraft can damage the hearing of pilots who are exposed to this hazard for many hours. A Boeing 727 co-pilot collected 61 noise observations using a handheld sound meter. Noise level is defined as “Low” (under 88 decibels), “Medium” (88 to 91 decibels), or “High” (92 decibels or more). There are three flight phases (Climb, Cruise, Descent). Research question: At α = .05, is the cockpit noise level independent of flight phase?

a. At the 0.05 level of significance, determine if cockpit noise level is independent of flight phase. State your hypotheses and show all 7 steps clearly. Be sure to write a conclusion that clearly and completely addresses the research question.

b. Give and interpret the p-value. c. Attach or include your Minitab output.

Flight Phase

Noise Level Climb Cruise Descent Row Total

Low 6 2 6 14

Medium 18 3 8 29

High 1 3 14 18

Col Total 25 8 28 61

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2. In a four-digit lottery, each of the four digits is supposed to have the same probability of occurrence. The table shows the frequency of occurrence of each digit for 89 consecutive daily four-digit drawings. Research question: At α = .01, can you reject the hypothesis that the digits are from a uniform population? Why do the frequencies add to 356?

a. At the 0.01 level of significance, determine if the digits are from a uniform population. State your hypotheses and show all 7 steps clearly. Be sure to write a conclusion that clearly and completely addresses the research question.

b. Give and interpret the p-value. c. Explain why the frequencies add to 356 d. Attach or include your Minitab output.

Digit Frequency

0 39 1 27 2 35 3 39 4 35 5 35 6 27 7 42 8 36 9 41

Total 356