It is thought that prehistoric Indians did not take their best tools, pottery, and household items when they visited higher elevations for their summer camps. It is hypothesized that archaeological...

It is thought that prehistoric Indians did not take their best tools, pottery, and household items when they visited higher elevations for their summer camps. It is hypothesized that archaeological sites tend to lose their cultural identity and specific cultural affiliation as the elevation of the site increases. Let
x
be the elevation (in thousands of feet) of an archaeological site in the southwestern United States. Let
y
be the percentage of unidentified artifacts (no specific cultural affiliation) at a given elevation. The following data were obtained for a collection of archaeological sites in New Mexico.

Complete parts (a) through (e), given Σx
= 31.37, Σy
= 161, Σx
²
= 199.2325, Σy
²
= 6747, Σxy
= 1064.43, and
r
≈ 0.884.

(b) Verify the given sums Σx, Σy, Σx
², Σy
², Σxy, and the value of the sample correlation coefficient
r. (Round your value for
r
to three decimal places.)

(c) Find x, and y. Then find the equation of the least-squares line =
a
+
bx. (Round your answers for x and y to two decimal places. Round your answers for
a
and
b
to three decimal places.)