Meteorology: Cyclones Can a low barometer reading be used to predict maximum wind speed of an approaching tropical cyclone? Data for this problem are based on information taken from Weatherwise (Vol. 46, No. 1), a publication of the American Meteorological Society. For a random sample of tropical cyclones, let x be the lowest pressure (in millibars) as a cyclone approaches, and let y be the maximum wind speed (in miles per hour) of the cyclone.

(a) Make a scatter diagram and draw the line you think best fi ts the data.

(b) Would you say the correlation is low, moderate, or strong? positive or negative?

(c) Use a calculator to verify that x 5 5823, x2 5 5,655,779, y 5 580, y2 5 65,750, and xy 5 556,315. Compute r. As x increases, does the value of r imply that y should tend to increase or decrease? Explain.

x 1004 975 992 935 985 932 y 40 100 65 145 80 150