Question

7. A sales manager collected the following data on annual sales for new customer accounts and the number of years of experience for a sample of 10 salespersons

Answer 1

SolutionA:

Use R software:

plot function is to get the scatterplot

plot(x,y)

Rcode:

yearsofexperience <- c(1,3,4,4,6,8,10,10,11,13)
annualsales <- c(80,97,92,102,103,111,119,123,117,136)
plot(yearsofexperience,annualsales)

from scatterlot

we observe:

form:linear

strength:strong

direction:positive

Solutionb:

use lm function to fit a model.

model <- lm(annualsales~yearsofexperience)
coefficients(model)

Output:

(Intercept) yearsofexperience
80 4

Regression equation is

annualsales=80+4*years of experience

slope=4

y intercept=80

Solutionc:

annualsales=80+4*years of experience

we need to predict annualsales for years of experience =9

annualsales=80+4*9=116

ANSWER:$ 116000