The Professor's Response

Hello professor,

on 10.1 "Do It Yourself!" problem 1 i noticed that mmy calculator does not round as exact as your answers but im doing all the work properly and in the correct steps. I have a scientific calculator but not graphing calculator will you calculate these differences on the third exam? for example for the SSE on that particular problem my answer was: 2075910.519 while on the given answer it stated 2,075,911.429

See the professor's answer below.

Hi Daniela,

I am not sure why your calculator would round these answers at all. Do me a favor, check your work against my calculations below. If any are different that will explain the discrepancy. I don't think it is the rounding, but it could be.

Correction Factor = (sum of the values)^2 / n = (7080+5970+10430)^2 / (15+14+14) = 12,821,172.09

SStotal = Sum of y-squared - CF = 15,733,800 - 12,821,172.09 = 2,912,627.907

SST = 7080²/15 + 5970²/14 + 10430²/14 - 12,821,172.09 = 836,716.4784

SSE = SStotal - SST = 2,912,627.907 - 836,716.4784 = 2,075,911.429

Let me know if you find an error in your work or if it is the calculator,

Professor McGuckian