2 1. POTTERY A local university is keeping track of the number of art students who use the pottery studio each day. Day 1 2 3 4 5 6 7 Students 10 15 18 15 19 20 a. Write an equation of the regression line and find and interpret the correlation coefficient b. Graph the residual plot and determine if the regression line models the data well. of stolen bases (SB) and times caught

4932,9180,7625 are divisible by 9

x^2 + 81

we can factor this using difference of square binomials.

rewrite the equation:

x^2 - (-81)

factor:

(a^2 - b^2) = (√a^2 + √b^2)(√a^2 - √b^2)

(x^2 - (-81) = (x + √-81)(x - √-81)

we can remove the - from under the radical by multiplying it by i.

(x^2 - (-81) = (x + i√81)(x - i√81)

(x^2 - (-81) = (x + 9i)(x - 9i)

we can check our answer by using foil:

x^2 - 9ix + 9ix - 81i^2

x^2 - 81^2

i^2 = -1

x^2 + 81