Question

Problem Problem Statement Gazelle wants to determine the level of customer satisfaction with her new artisinal spark plugs, so she conducts a survey with 10 subjects and obtains these ratings: 90.2 95.189.0 99.096.0 89.1 96.9 98.4 97.5 92.2 Gazelle thinks that the customer scores are normally distributed, with arn unknown mean and variance. She wants to determine if the true mean cus tomer satisfaction rating is different from 90, and she wl be interested in whether or not it is higher or lower than 90, and she would like to conduct her test with a signficance level of α-0.05. Part (a) State the null and alternative hypotheses, and indicate what kind of test is appropriate. Part (b) Calculate the sample mean and sample variance for this data. Part (c) Conduct a hypothesis test for the nul hypothesis in part (a). Part (d) Construct a 95% confidence interval for the true mean customer satisfaction rating using this data.

Answer 1

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