Question

The cost of a leading liquid laundry detergent in different sizes is given below.

Size (ounces)	Cost ($)	Cost per ounce
16	3.99
32	4.59
64	5.89
200	10.19

Part (a)

Calculate the least squares line. Put the equation in the form of:

? = a + bx.

(Round your answers to three decimal places.)
? = _______+ __________x

Answer 1

The statistical software output for this problem is:

Simple linear regression results:
Dependent Variable: Cost ($)
Independent Variable: Size (ounces)
Cost ($) = 3.5617871 + 0.033374525 Size (ounces)
Sample size: 4
R (correlation coefficient) = 0.99889436
R-sq = 0.99778994
Estimate of error standard deviation: 0.16110361

Parameter estimates:

Parameter	Estimate	Std. Err.	Alternative	DF	T-Stat	P-value
Intercept	3.5617871	0.11829476	? 0	2	30.109424	0.0011
Slope	0.033374525	0.0011106632	? 0	2	30.049184	0.0011

Analysis of variance table for regression model:

Source	DF	SS	MS	F-stat	P-value
Model	1	23.435591	23.435591	902.95349	0.0011
Error	2	0.051908745	0.025954373
Total	3	23.4875

Hence,

Regression equation will be:

? = 3.562 + 0.033 x