Question

Regression Analysis

Y = Price in $’s for Tracfone service plan

X1 = No. of minutes in plan

X2 = No. of service days in plan

(a) Write the equation in numerical form based on the MegaStat output below.

(b) Evaluate the equation statistically.

(c) Predict the change in the service plan price if the number of minutes increases by 100. (Note: Price is in $’s)

(d) Predict the change in the service plan price if the number of days increases by 100. (Note: Price is in $’s)

(e) Predict the price for a plan which offers 100 minutes and 100 days. (Note: Price is in $’s).

Regression Analysis
	R²	0.954
	Adjusted R²	0.944	n	12
	R	0.977	k	2
	Std. Error	13.321	Dep. Var.	Price, $'s
Regression output					confidence interval
variables	coefficients	std. error	t (df=9)	p-value	95% lower	95% upper
Intercept	20.0000	6.8759	2.517	.0329	1.7504	32.8590
X1, minutes	0.1000	0.0092	12.488	5.48E-07	0.0936	0.1350
X2, days	0.0800	0.0263	2.680	.0252	0.0110	0.1297

Answer 1

a & b)

Equation in numerical form is given as

Intercept =20

Regression coefficient for minutes=0.1

Regression coefficient for days =0.08

Regression equation is given as

c)

We have to Predict the change in the service plan price if the number of minutes increases by 100.

Predicted change in service plan will be =0.1(100)=$10

d)

Predict the change in the service plan price if the number of days increases by 100. will be

=0.08(100)=$8

e)

Predict the price for a plan which offers 100 minutes and 100 days

Regression equation is given as

Put minutes=100 & days=100

Predicted  price for a plan which offers 100 minutes and 100 days will be $38