He made 36 peanut butter so in total he made 48 cookies
A) T(m) = -0.16m +331.3
B) T(2015) = 8.9 . . . seconds
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The linear regression function of a graphing calculator can find the equation of the line easily. Or, you can use the 2-point form of the equation of a line.
.. T(m) = (10.5 -14.5)/(2005 -1980)*(m -1980) +14.5
.. T(m) = -0.16(m -1980) +14.5
Couldn't it be 54, 53 52, or 51