For Exercises 2.1 and 2.2, pages 64–65; for 2.3 and 2.4, see page 65; for 2.5 and 2.6, pages 66–67; and for 2.7, see page 68.

Question 2.19

2.19 Time to start a business

tts

Case 1.2 (page 23) uses the World Bank data on the time required to start a business in different countries. For Example 1.21 and several other examples that follow we used data for a subset of the countries for 2013. Data are also available for times to start in 2008. Let's look at the data for all 189 countries to examine the relationship between the times to start in 2013 and the times to start in 2008.

  1. Why should you use the time for 2008 as the explanatory variable and the time for 2013 as the response variable?
  2. Make a scatterplot of the two variables.
  3. How many points are in your plot? Explain why there are not 189 points.
  4. Describe the form, direction, and strength of the relationship.
  5. Identify any outliers.
  6. Is the relationship approximately linear? Explain your answer.

2.19

(a) 2008 data should explain the 2013 data. (c) There are 182 points; some of the data for 2008 are missing. (d) The form is somewhat linear; the direction is positive; the strength is moderate. (e) Suriname is an outlier for both 2008 and 2013. (f) The relationship is somewhat linear, though there are observations that don't follow the linear trend well.