2.31 Frequency tables, histograms, and life expectancy rates: The United Nations Development Programme (2015) published life expectancy rates—the number of years an adult can expect to live—for 195 countries around the world. Following is a randomly selected sample of 30 of them.

Country Life expectancy (years) Country Life expectancy (years) Afghanistan 60.95 Lebanon 80.01 Armenia 74.56 Malaysia 75.02 Australia 82.50 Mexico 77.50 Belarus 69.93 Namibia 64.48 Bosnia and Herzegovina 76.37 New Zealand 81.13 Burkina Faso 56.34 Panama 77.56 Canada 81.48 Saint Lucia 74.80 Côte d’Ivoire 50.72 Slovakia 75.40 Cuba 79.26 Sweden 81.82 Ecuador 76.47 Tonga 72.67 Ghana 61.13 Trinidad and Tobago 69.87 Guyana 66.30 Tunisia 75.87 Indonesia 70.83 United Kingdom 80.55 Japan 83.58 United States 78.94 Jordan 73.85 Zimbabwe 59.87

a. Create a grouped frequency table for these data.

b. The data have quite a range, with the lowest life expectancy of 50.72 years in Côte d’Ivoire and the highest life expectancy of 83.58 years in Japan. What research hypotheses come to mind when you examine these data? State at least one research question that these data suggest to you.

c. Create a grouped histogram for these data. As always, be careful when determining the midpoints of the intervals.

d. Examine the histogram and give a brief description of the distribution. Are there unusual scores? Are the data symmetric, or are they skewed? If they are skewed, in which direction?