Answered

Get the answers you need at Westonci.ca, where our expert community is dedicated to providing you with accurate information. Join our platform to connect with experts ready to provide accurate answers to your questions in various fields. Get immediate and reliable solutions to your questions from a community of experienced professionals on our platform.

A random sample of the costs of repair jobs at a large muffler repair shop produces a mean of $127. 95. And a standard deviation of $24. 3. If the size of this sample is 40, which of the following is an approximate 90 percent confidence interval for the average cost of a repair at this repair shop?.

Sagot :

abidemiokin

The confidence interval for the average cost of a repair at this repair shop is [tex]127.95\pm6.321[/tex]

Confidence interval

The formula for calculating the z-score is expressed as:

[tex]CI = \overline x \pm z\frac{s}{\sqrt{n} }[/tex]

Given the following

  • mean = 127. 95
  • z = 1.645
  • s = 24.3
  • n = 40

Substitute the given parameters

[tex]CI = 127.95 \pm 1.645*\frac{24.3}{\sqrt{40} }\\CI = 127.95 \pm 1.645*\frac{24.3}{6.324 }\\CI = 127.95 \pm 6.321[/tex]

Hence the confidence interval for the average cost of a repair at this repair shop is [tex]127.95\pm6.321[/tex]

Learn more on confidence interval here: https://brainly.com/question/15712887

We hope you found what you were looking for. Feel free to revisit us for more answers and updated information. We appreciate your time. Please revisit us for more reliable answers to any questions you may have. Get the answers you need at Westonci.ca. Stay informed with our latest expert advice.