Question

Is the magnitude of an earthquake related to the depth below the surface at which the quake occurs? Let x be the magnitude of an earthquake (on the Richter scale), and let y be the depth (in kilometers) of the quake below the surface at the epicenter.

x	3.1	4.6	3.3	4.5	2.6	3.2	3.4
y	4.8	9.8	11.2	10.0	7.9	3.9	5.5

(a) Make a scatter diagram of the data.

Then visualize the line you think best fits the data.

(b) Use a calculator to verify that Σx = 24.7, Σx² = 90.47, Σy = 53.1, Σy² = 452.39 and Σxy = 193.64.

Compute r. (Round to 3 decimal places.)


As x increases, does the value of r imply that y should tend to increase or decrease? Explain your answer.

Given our value of r, y should tend to decrease as x increases.

Given our value of r, y should tend to remain constant as x increases.  

Given our value of r, we can not draw any conclusions for the behavior of y as x increases.

Given our value of r, y should tend to increase as x increases.

Answer 1

a)

b)

Given our value of r, y should tend to increase as x increases.