Question

136 CHAPTER 6 Association between Quantitative Variables of mistakes made by 15 data entry clerks who enter medical data from case report forms. T are submitted ies of the perform illnesses. The column Entered indicates the number hese forms by doctors who participate in stud- ance of drugs for treating various of values entered, and the column Errors gives the number of coding errors that were detected among 38 4,434 15 49 (a) Make a scatterplot of these data and describe the direction, form, and scatter of the plot (b) Find the correlation. (c) If the trucks were weighed in kilograms, 18 3,303 how would this change the correlation? (d) Interpret the correlation in the context of trucks of c 36 23 and weights. What does the corelation tell the Minnesota Department of Transportation? 45. Cars These data report characteristics of 413 types of cars sold in the United States in 2016. One col- umn gives the official mileage (combined MPG), and another gives the rated horsepower a) Make a scatterplot of these two columns. 3,4 Which variable makes the most sense to put on (b) Describe any pattern that you see in the plot. Be (c) Find the correlation between these two variables the x-axis, and which belongs on the y-axis? (a) Make a scatterplot of these data. Which did sure to identify any outliers. you choose for the response and which for the explanatory variable? Describe any pattern (d) Interpret the correlation in the context of these (b) Find the correlation for these data (c) Suppose we were to record the counts in the data. Does the correlation provide a good sum- (e) Use the correlation line to estimate the mileage (d mary of the strength of the relationship? table in hundreds, so 4,434 became 44.34. How would the correlation change? Why? of a car with 200 horsepower. Does this seem like a sensible procedure (d) Write a sentence or two that interprets the value of this correlation. Use language that would be 46. Cars These data are described in Exercise 45 understood by someone familiar with data entry rather than correlations. (a) Make a scatterplot of weight and city mileage ti Which variable do you think makes the most (e) One analyst concluded, "It is clear from this cor sense to put on the x-axis, and which belongs on the y-axis? relation that clerks who enter more values make more mistakes. Evidently they become tired as they enter more values." Explain why this expla nation is not an appropriate conclusion. (b) Describe any pattern that you see in the plot. Be sure to identify any outliers. (c) Find the correlation between these two variables. (d) Use the correlation line to estimate the mileage of a car that weighs 4,000 pounds. Does this 44. Truck Weight The Minnesota Department of ion would like to measure the weights ial trucks on its highways without the seem like a sensible procedure? of maintaining weigh stations along the Weigh stations are expensive to operate, 47. Philadelphia Housing These data describe housing highway. delay shipments, and aggravate truck prices in the Philadelphia area. Each of the 110 rows of this data table describes a region of the metropolitar area. (Several make up the city of Philadelphia.) One ers. To see ed remote weight system was accurate on officials conducted a test. They D, transportrucks when stopped on a regular scale. column, labeled Selling Price, gives the median price used the remote system to estimate the for homes sold in that area during 1999 in thousands of eights. Here are the data. dollars. Another, labeled Crime Rate, gives the numbern of crimes committed in that area, per 100,000 residents. Rubir

2) Do question 43 of page 135-36 in your text book. Show your work in excel file. could you please pdf it to me

Answer 1

(a)

From the above graph we observe that there exist a positive relationship between the given two variables.