Two hundred people were randomly selected in the year 2010 (group 1) and in the year 2012 group 2). They were asked how many hours a day they spent on a digital device (online, mobile, or other). The sample mean in 2010 was 3.14 hours and in 2012 it was 4.31 hours. What is the point estimate of the population mean difference between 2010 and 2012?

A press organization was interested in studying people’s voting habits. One hundred randomly selected registered voters over the age of 50 and one hundred randomly selected voters between the ages of 30 and 50 were asked if they had decided who they were going to vote for in the presidential election.  Would this be an example of independent or dependent samples?

For the hypothesis statements, Ho:p1-p2=0 versus Ha:p1-p2 > 0 if the TS equals 2.3, what is the p-value?  

Is there a difference in the attitude scores (1-10) about learning statistics between underclassmen and upperclassmen students?  What would be the correct alternative hypothesis?

A nutritionist was interested in studying American’s opinions about healthy eating. One hundred randomly selected people who were starting a diet were asked if they ate five servings of fruit or vegetables a day. After six months, the same 100 people were asked if they ate five servings of fruit or vegetables a day.   Six months later “Yes, ate 5 servings” Six months later “No, did not eat five servings” Initial Response “Yes, ate five servings” 20 50 Initial Response “No did not eat five servings” 17 13  What is the sample proportion that ate 5 servings a day initially?

A nutritionist was interested in studying American’s opinions about healthy eating. One hundred randomly selected people who were starting a diet were asked if they ate three servings of whole grains a day. After six months, the same 100 people were asked if they ate three servings of whole grains a day. Besides random sampling and categorical data, what other assumption needs to be met? Is it met?   Six months later “Yes, ate whole grains” Six months later “No, did not” Initial Response “Yes, ate whole grains” 26 15 Initial Response “No did not” 17 42

A study was done to see if students who took AP Calculus  before taking the AP statistics course did better than students who did not take AP Calculus. They wanted to see if there was a difference in the AP Statistics exam scores. The p-value was 1.0. What does this mean?

Researchers want to determine if there is a connection between choice of musical instruments and gender. They want to see if the proportion of men (m) who play the flute is different from the proportion of women (f) who play the flute. They find that the p-value is 0.11.   What can be said about the 99% confidence interval for the population mean difference?

Do less men(m) then women(f) enroll in engineering courses? What would be the correct alternative hypothesis?

A nutritionist was interested in studying American’s opinions about healthy eating. One hundred randomly selected people who were starting a diet were asked if they ate five servings of fruit and vegetables every day. After six months, the same 100 people were asked if they ate five servings of fruits and vegetables a day. What is the value of the test statistic?   Six months later “Yes, ate five servings of fruit and vegetables” Six months later “No, did not” Initial Response “Yes, ate five servings” 17 18 Initial Response “No did not” 46 19