The data file TVLife provides information on life expectancy and number of televisions per thousand people in a sample of 22 countries, as reported by the 2006 World Almanac and Book of Facts. Enter the data into the Corr/Regression applet.
a. Identify the type of study: randomized experiment or observational study.
b. Identify the experimental/observational units in this study. (Hint: “People” is not the answer.)
c. Produce a scatterplot using life expectancy as the response variable and number of TVs per 1,000 as the explanatory variable. Comment on the association between the variables as revealed in the scatterplot. (Remember to comment on form, direction, strength, and unusual observations.)
d. Report the value of the correlation coefficient. Does the value of the correlation coefficient support your answer in part (c)? Explain how you are deciding.
e. As you (should) have discovered in parts (c) and (d), the association between life expectancy and number of televisions per thousand people appears pretty strong. Based on this finding, is it okay to conclude that simply sending televisions to the countries with lower life expectancies would cause their inhabitants to live longer? Explain why or why not.