World Health In general, people tend to live longer in

Chapter , Problem 60A

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Problem 60A

World Health In general, people tend to live longer in countries that have a greater supply of food. Listed below is the 2003–2005 daily calorie supply and 2005 life expectancy at birth for 10 randomly selected countries. Source: Food and Agriculture Organization.

Country	Calories (x)	Life Expectancy (y)
Belize	2818	75.4
Cambodia	2155	59.4
France	3602	80.4
India	2358	62.7
Maxico	3265	75.5
New Zealand	3235	79.8
Peru	2450	72.5
Sweden	3120	80.5
Tanzania	2010	53.7
United States	3826	78.7

a. Find the correlation coefficient. Do the data seem to fit a straight line?

b. Draw a scatterplot of the data. Combining this with your results from part a, do the data seem to fit a straight line?

c. Find the equation of the least squares line.

d. Use your answer from part c to predict the life expectancy in the United Kingdom, which has a daily calorie supply of 3426. Compare your answer with the actual value of 79.0 years.

e Briefly explain why countries with a higher daily calorie supply might tend to have a longer life expectancy. Is this trend likely to continue to higher calorie levels? Do you think that an American who eats 5000 calories a day is likely to live longer than one who eats 3600 calories? Why or why not?

f. (For the ambitious!) Find the correlation coefficient and least squares line using the data for a larger sample of countries, as found in an almanac or other reference. Is the result in general agreement with the previous results?