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Chapter 3: Q T3.9. (page 216)

The scatterplot shows the relationship between the number of people per television set and the number of people per physician for 40 countries, along with the least-squares regression line. In Ethiopia, there were 503 people per TV and 36,660 people per doctor. Which of the following is correct?

a. Increasing the number of TVs in a country will attract more doctors.

b. The slope of the least-squares regression line is less than 1.

c. The correlation is greater than 1.

d. The point for Ethiopia is decreasing the slope of the least-squares regression line.

e. Ethiopia has more people per doctor than expected, based on how many people it has per TV.

Short Answer

Expert verified

The correct option is (e).

Step by step solution

01

Given information

02

Explanation

The data points are above the regression line in the preceding plot, indicating that the actual individual per person is smaller than the projected people per doctor. Option (e) appears to be the most appropriate of the possibilities presented. Hence, the correct option is (e).

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Most popular questions from this chapter

Correlation isn’t everything Marc and Rob are both high school English teachers. Students think that Rob is a harder grader, so Rob and Marc decide to grade the same 10 essays and see how their scores compare. The correlation is r=0.98 but Rob’s scores are always lower than Marc’s. Draw a possible scatterplot that illustrates this situation.

Calculating achievement a study found a strong link between the number of calculators possessed by high school pupils and their arithmetic proficiency, according to the principle of a high school. Based on this study, he decides to buy each student at his school two calculators, hoping to improve their math achievement. Explain the flaw in the principal’s reasoning.

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Will I bomb the final? We expect that students who do well on the midterm exam in a course will usually also do well on the final exam. Gary Smith of Pomona College looked at the exam scores of all 346 students who took his statistics class over a 10-year period. Assume that both the midterm and final exams were scored out of 100 points.

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