1. 8A researcher studies the average distance that 130 people living in U.S. urban areas walk each week.
a. What is the size of the sample?
b. Identify the population.
c. Is this "average" a descriptive statistic or an inferential statistic if it is used to describe the 130 people studied?
d. How might you operationalize the average distance walked in 1 week as an ordinal measure?
e. How might you operationalize the average distance walked in 1 week as a scale measure?
2. Sample versus population in Norway: The NordTrøndelag health study surveyed more than 60,000 people in a Norwegian county and reported that gastrointestinal symptoms, depression, and anxiety disorders are strongly related (Haug, Mykletun, & Dahl, 2002).
a. What is the sample used by these researchers?
b. What is the population to which the researchers would like to extend their findings?
3. Types of variables and the Kentucky Derby: The Kentucky Derby is perhaps the premier event in U.S. horse racing. For each of the following examples from the derby, identify the type of variable-nominal, ordinal, or scale.
a. As racing fans, we would be very interested in the variable finishing position. A horse called Orb won in 2013, followed by Golden Soul in second and Revolutionary in third.
b. We also might be interested in the variable finishing time. Orb won in 2 minutes, 2.89 seconds.
c. Derby attendance was 151,616 in 2013, not as high as the record-setting 165,307 people who attended in 2012.
d. If we were the betting type, we might examine the variable payoffs. For each $2.00 bet on Orb, a gambler won $12.80.
e. We might be interested in the history of the Derby and the demographic variables of jockeys, such as gender or race. For example, in the first 28 runnings of the Kentucky Derby, 15 of the winning jockeys were African American.
f. In the luxury boxes, high fashion reigns; we might be curious about the variable hat wearing, observing how many women wear hats and how many do not.
Calculating the Statistics
1. Convert the following to percentages: 63 out of 1264; 2 out of 88.
2. Throughout this book, final answers are reported to two decimal places. Report the following numbers this way: 1,888.999, 2.6454, and 0.0833.
3. A grouped frequency table has the following intervals: 30-44, 45-59, and 60-74. If converted into a histogram, what would the midpoints be?