Two hundred people were randomly selected in the year 2012 (group 1) and in the year 2013 (group 2). They were asked how many hours a day they spent listening to a radio. The sample mean in 2012 was 1.32 hours and in 2013 it was 1.26 hours. What is the point estimate of the population mean difference between 2012 and 2013?

In 2010 and 2012, Gallup asked the same 50 people how many hours had they worked at a job in the past 7 days. Is there a difference in the population mean amount of hours worked at a job between 2010 and 2012? Would this be an example of independent or dependent samples?

An informed college student wants to test samples of water in water fountains on campus to ensure that the average amount of lead is less than 15 ppb. What would be the appropriate alternative hypothesis?

A scientist was interested in determining if the Paleo diet plan worked.  They randomly selected 4 people that were interested in trying a new diet plan. They recorded their initial weights before starting the diet plan. After six weeks, their weight was taken again. How would you check the normality assumptions for this test?     1 2 3 4 Initial weight 150 167 129 194 Weight six weeks later 172 157 124 190

Let alpha = 0.05. Suppose that you were testing Ho:mu = 30 versus Ha: mu greater than 30. If you had a p-value of 0.03, what decision would you make?

In the US, the allowable amount of mercury in drinking water is 2 parts per 1000 Liters. Water from 5 randomly selected homes was taken. The amount of mercury in the water is below. A scientist wants to test to see if the amount of mercury is unsafe. These measurements are also in parts per 1000 Liters. 1 0 0.5 0 1   Find the standard error that would be used in the test statistic to test this claim.

A study was done by Sananman and Lear in the 1960s to monitor the amount of iron (mg/L) in the water in the Chesapeake Bay. They compared the amount of iron from a depth of 10 feet (group 1) to a depth of 100 feet (group 2). The researchers were interested in determining if the amount of iron was different at the two depths. The 95% confidence interval to compare the two depths is (-0.20, -0.13). Interpret the confidence interval.   We are 95% confident that  . . .

In the US, the allowable amount of mercury in drinking water is 2 parts per 1000 Liters. Water from 5 randomly selected homes was taken. The amount of mercury in the water is below. A scientist wants to test to see if the amount of mercury is unsafe. These measurements are also in parts per 1000 Liters. 0 0.5 0.5 0.5 1   Find the standard error that would be used in the test statistic to test this claim.

A nutritionist was interested in studying American’s opinions about healthy living. One hundred randomly selected people who were starting a diet were asked if they consumed at least 24 ounces of water a day. After six months, the same 100 people were asked if they consumed at least 24 ounces of water a day   Six months later “Yes, consumed at least 24 ounces of water” Six months later “No, did not” Initial Response “Yes, consumed at least 24 ounces of water” 25 20 Initial Response “No did not” 30 25   What is the sample proportion of people who responded “Yes, they consumed at least 24 ounces of water” six months later?

In 2014, the General Social survey was interested in studying individuals volunteering habits.They randomly selected 580 men and 689 women and then asked them if they had volunteered in the last month. Out of 580 men, 34 said that they had volunteered in the past month and out of 689 women, 37 said that they had volunteered in the past month. Suppose that you want to make a 95% confidence interval for  , what assumption is violated in this case?