11. The relationship between total fertility rate and the prevalence of contraceptive practice was investigated for a large number of countries around the world [5]. Measuring fertility rate in births per woman 15 to 49 years of age and the proportion of currently married women using any form of contraception as a percentage, the least-squares regression line relating these two quantities is y = 6.83 - 0.062x. For the subset of 17 countries in the sub-Saharan region of Africa, fertility rate and the prevalence of contraceptive practice are saved in a data set called a frica (Ap- pendix B, Table B.24). Measures of fertility rate are saved under the variable name fertrate, and values of percentage contraception under contra. (a) Interpret the slope and the intercept of the least-squares regression line generated for the countries around the world. What do they imply in words? (b) Using the data for the 17 sub-Saharan African countries, construct a two-way scatter plot of total fertility rate versus prevalence of contraceptive practice. Does there appear to be a relationship between these two quantities TABLE B.24 Data set africa; variables country, fer- trate, and contra Benin 7.1 9 Botswana 5.0 33 Burundi 6.8 9 Cameroon 6.4 Cote d'Ivoire 7.4 Ghana 6.4 13 Kenya 6.7 27 Lesotho 5.8 7 Liberia 6.6 7 Mali 6.7 5 Nigeria 6.2 6 Rwanda 8.5 10 Senegal 6.6 11 Sudan 5.9 6 Togo 6.2 34 Uganda 7.3 5 Zimbabwe 5.7 43 (c) On the scatter plot, sketch the least-squares line estimated based on countries throughout the world. (e) How do the actual fertility rates for the African nations compare with those that would be predicted based on the fitted regression line