Question

Can a low barometer reading be used to predict maximum wind speed of an approaching tropical cyclone? 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. x 1004 975 992 935 981 930 y 40 100 65 145 78 149 (a) Make a scatter diagram of the data and visualize the line you think best fits the data. (b) Would you say the correlation is low, moderate, or strong? low moderate strong Use a calculator to verify that (c) Use a calculator to verify that x = 5817, x2 = 5,644,191, y = 577, y2 = 65,135 and xy = 552,803. Compute r. (Round your answer to three decimal places.)

Answer 1

	X	Y	X * Y	X2	Y2
	1004	40	40160	1008016	1600
	975	100	97500	950625	10000
	992	65	64480	984064	4225
	935	145	135575	874225	21025
	981	78	76518	962361	6084
	930	149	138570	864900	22201
Total	5817	577	552803	5644191	65135

There is negative and strong correlation between variables.

r = -0.990