A study claims that all adults spend an average of 14 hours or more on chores during a weekend. A researcher wanted to check if this claim is true. A random sample of 200 adults taken by this researcher showed that these adults spend an average of 14.65 hours on chores during a weekend. The population standard deviation is known to be 3.0 hours. Test the hypothesis of part a using the critical-value approach and ?

Suppose that El Camino is studying the average number of hours students study for classes per week. According to research from 2010 El Camino students spent an average of 21 hours a week studying for classes. El Camino wants to study if this average has changed. To do this they take a random sample of 81 current students and find that the average student spent 19.3 hours studying with a standard deviation of 6.4 hours. (Note: You may assume there are approximately 20,000 El Camino students). (a) Carry out a hypothesis test at α = .05 to test the claim that the average number of hours per week that El Camino students study has changed since 2010. (b) Describe what it would mean in this situation to make a Type I error (c) Describe what it would mean in this situation to make a Type II error (d) Construct a 95% confidence interval for the average number of hours studied by El Camino students per week. Make sure to interpret your interval.

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…

Bone mineral density (BMD) is a measure of bone strength. Studies show that BMD declines after age 45. The impact of exercise may increase BMD. A random sample of 59 women between the ages of 41 and 45 with no major health problems were studied. The women were classified into one of two groups based upon their level of exercise activity: walking women and sedentary women. The 39 women who walked regularly had a mean BMD of 5.96 with a standard deviation of 1.22. The 20 women who are sedentary had a mean BMD of 4.41 with a standard deviation of 1.02. Which of the following inference procedures could be used to estimate the difference in the mean BMD for these two types of women