(b)Zhelong claimed she needs different to 29 minutes on average to repair brokencustomers' computers. A total of 20 computers left by customers were randomlyselected. Through the record from the sample, the average time taken was 28.5 minuteswith a standard deviation of 2.5 minutes. Assume the time is normally distributed.(i)Determine is the population standard deviation given for the above case study?(ii)Test the claim at a 5% significance level using a critical value approach.

Answered: Image /qna-images/answer/bedb7a2d-cf1a-46b2-afe0-d2cc6a2f7243.jpg

Answered: Zhelong claimed she needs different to…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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You are the manager of a restaurant for a fast-food franchise. Last month, the mean waiting time at the drive through window for branches in your geographical region, as measured from the time a customer places an order until the time the customer receives the order, was 38 minutes. You select a random sample of 81 orders. The sample mean waiting time is 367 minutes, with a sample standard deviation of 0 96 minute Complete parts (a) and (b) below a. At the 0.05 level of significance, is there evidence that the population mean waiting time is different from 38 minutes? State the null and atemative hypotheses H₂ P H₁ PY (Typo integers or decimals)
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The mean age when smokers first start is 13 years old with a population standard deviation of 1.8 years. A researcher thinks that smoking age has significantly changed since the invention of ENDS—electronic nicotine delivery systems. A survey of smokers of this generation was done to see if the mean age has changed. The sample of 33 smokers found that their mean starting age was 12.3 years old. Do the data support the claim at the 5% significance level? What are the correct hypotheses? Based on the hypotheses, find the following: Test Statistic z = (Give answer to at least 2 decimal places) From the table(https://ma336.qccmathcs.com/ ), Find p-value = (Give answer to at least 4 decimal places)
Is there strong evidence of global warming? Let’s consider a small scale example, comparing how temperatures have changed in the US from 1968 to 2008. The daily high temperature reading on January 1 was collected in 1968 and 2008 for 51 randomly selected locations in the continental US. Then the difference between the two readings (temperature in 2008 - temperature in 1968) was calculated for each of the 51 different locations. The average of these 51 values was 1.1 degrees with a standard deviation of 4.9 degrees. We are interested in determining whether these data provide strong evidence of temperature warming in the continental US. (d) Calculate the test statistic and find the p-value. (e) What do you conclude? Interpret your conclusion in context. (f) Calculate a 90% confidence interval for the average difference between the temperature measurements between 1968 and 2008. Interpret this interval in context. (g) Does the confidence interval provide convincing evidence that the…
You are the manager of a restaurant for a fast-food franchise. Last month, the mean waiting time at the drive-through window for branches in your geographical region, as measured from the time a customer places an order until the time the customer receives the order, was 3.8 minutes. You select a random sample of 81 orders. The sample mean waiting time is 3.66 minutes, with a sample standard deviation of 0.9 minute. Complete parts (a) and (b) below. a. At the 0.10 level of significance, is there evidence that the population mean waiting time is different from 3.8 minutes? State the null and alternative hypotheses. Ho H (Type integers or decimals.)
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