13.7. For 49 pieces of 1=6-in. poplar (wood) about 110 51 in., a study was made of wet, x, vs. dry, y, lengths.

This was to study the shrinkage so as to control y to specification needs. The following results were found:

P P x¼5523, y¼5162 in, and n P

x2(

P x)2¼19,600, n P

y(

P y)2¼

23,672, n P

xy(

P x)(

P y)¼17,584.

a. Find x, y, sy, bo, b1, r, and syx.

b. Test r for significance.

c. Write the estimation equation, and estimate y for x¼109 and 119.