A SAMPLE SIZE OF 36 WAS DRAWN AND ITS MEAN WAS FOUND TO BE80. TEST WHETHER THIS SAMPLE COULD HAVE COME FROM A NORMALPOPULATION WITH MEAN 90 AND VARIANCE 225?Your answer

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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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A sample of seven laptop computers had a variance of 25.88 years when the lifespan of the computer was studied. Find the 90% confidence interval for the true variance of the lifespan of laptop computers. Show all work leading up to your answer below
It currently takes users a mean of 26 minutes to install the most popular computer program made by RodeTech, a software design company. After changes have been made to the program, the company executives want to know if the new mean is now different from 26 minutes so that they can change their advertising accordingly. A simple random sample of 51 new customers are asked to time how long it takes for them to install the software. The sample mean is 24.9 minutes with a standard deviation of 2.7 minutes. Perform a hypothesis test at the 0.025 level of significance to see if the mean installation time has changed. Step 3 of 3 : Draw a conclusion and interpret the decision.
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A new drug is being tested to see if it reduces the frequency of migraines. Study participants were divided into two groups. 49 participants in group 1 received the medication; 42 participants in group 2 received a placebo. After a period of six months, group 1 had a mean of 4 migraines. It is known that the population standard deviation for this group is 1.3 migraines. Group 2 had a mean of 5.4 migraines. The population standard deviation for this group is 1.7 migraines. Can we conclude that the medication reduces the population mean number of migraines? Use αα =0.01. Note: If t-test, then unequal variances are assumed. Question a)Let: μ1μ1 = the population mean number of migraines with the medication μ2μ2 = the population mean number of migraines with the placebo (Step 1) State the null and alternative hypotheses by selecting the appropriate symbol, and identify which tailed test: H0:H0: μ1μ1 μ2μ2 H1:H1: μ1μ1 μ2μ2 Which tailed test…
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A SAMPLE SIZE OF 36 WAS DRAWN AND ITS MEAN WAS FOUND TO BE 80. TEST WHETHER THIS SAMPLE COULD HAVE COME FROM A NORMAL POPULATION WITH MEAN 90 AND VARIANCE 225?