<PRE><B>Question 1046605</B>
We need to do a linear regression analysis, the general equation is
:
y = b0 + (b1 * x)
:
let x be the hour/s of display and y be the cost
:
first step is to calculate the mean for x and the mean for y
:
x mean = (1 + 3 + 4 + 6 + 8) / 5 = 4.4
y mean = (150 + 175 + 185 + 200 + 300) / 5 = 202
:
now we can calculate
:
b1 = [summation of (xi - xmean) * (yi - ymean)] / [summation (xi -xmean)^2] = 571 / 29.2 = 19.5548
:
b0 = ymean - b1 * xmean = 202 - (19.5548 * 4.4) = 115.9589
:
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our linear regression equation is
:
y = 19.5548x + 115.9589
:
if x = 7, then
:
y = 19.5548*7 + 115.9589 = 252.8425 approx $253
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