Question

A study is conducted to determine the simple linear regression relation (if any) between average temperature over a week and ice-cream sales in a particular city. The following table provides the regression data required to construct the model:

Average Temperature and Ice-cream Sales
Average Temperature over a Week (°F)	Weekly Ice-cream Sales ($'000s)
38	95.512
78	139.092
39	96.298
49	108.688
89	152.288
56	116.48
71	132.61
70	130.454
95	159.834
72	133.896
96	159.75
55	114.594

Calculate the slope (b₁) and intercept (b₀) of the simple regression equation using the data provided. Give your answers to 2 decimal places.

(a)Slope = b₁ = ________

(b)Intercept = b₀ = _______

Answer 1

We have to find a slope and intercept.

= 67.3333

= 128.2913

n = 12

	x	y	xy	x^2
	38	95.512	3629.456	1444
	78	139.092	10849.18	6084
	39	96.298	3755.622	1521
	49	108.688	5325.712	2401
	89	152.288	13553.63	7921
	56	116.48	6522.88	3136
	71	132.61	9415.31	5041
	70	130.454	9131.78	4900
	95	159.834	15184.23	9025
	72	133.896	9640.512	5184
	96	159.75	15336	9216
	55	114.594	6302.67	3025
Total	808	1539.496	108647	58898

​​​​

a) Slope = b1 = 1.11

b)