Quiz 5

1.  Problem 1. The wind chill factor depends on wind speed and air temperature. The following data represent the wind speed, in mile per hour, and wind chill factor at an air temperature of 15◦ Fahrenheit.

(a) (2 points) Use StatCrunch to make a scatter diagram of the data with wind speed as the explanatory variable.
(b) (2 points) What is the correlation coefficient? Is there a linear relation between wind speed and wind chill factor?
(c) (2 points) Use StatCrunch to make a residual plot of the data.
(d) (2 points) Is the least-squares regression line is a good model for the data? Why?

2. Problem 2. Researchers conducted a study to determine which form of transportation, helicopter or ambulance, is more effective at saving lives when evacuating a victim from an accident. The data are below

(a) (1 point) Construct a conditional distribution of death and survival by mode of transportation.
(b) (1 point) Which mode a transportation appears to save more lives?

The data above does not take into account the severity of the accident. Below is the same data broken down by how
serious the accident was

(c) (1 point) For serious accidents, construct a conditional distribution of death and survival by mode of transportation.
(d) (1 point) For less serious accidents, construct a conditional distribution of death and survival by mode of transportation.
(e) (1 point) Taking into account how serious the accident was, which mode of transportation saves more lives?