Question

The number of disk drives (in millions) made at a plant in Brazil during the past 5 years follows:

Year	Disk Drives
1	140
2	160
3	190
4	200
5	210

a. Forecast the number of disk drives to be made next year, using trend analysis [ Select ] ["234", "196", "225", "236", "None of the choices provided are correct"]

b. Compute the mean squared error (MSE) when using linear regression. [ Select ] ["30.5", "30", "32", "33.5", "None of the choices provided are correct"]

c. Compute the mean absolute percent error (MAPE). [ Select ] ["2.50", "-2.50", "2.65", "2.12", "None of the choices provided are correct"] %

d. What is the Correlation Coefficient? [ Select ] ["None of the choices provided are correct", "88%", "90%", "95%", "98%"] , and what does it tell you about the relationship between the independent variable an dependent variable? [ Select ] ["cannot determine by calculating r", "A somewhat strong relationship based on r", "That there is a strong relationship", "A weak relationship between time and disk drivesand"]

Answer 1

i am using minitab to solve the problem.

steps for part a,b and c:-

copy the data table in minitabstat time series trend analysisin variable select disk drives,in model type tick linear,tick generate forecasts, in number of forecasts type 1 ok.

your minitab output be:-

Trend Analysis for Disk Drives

Method

Model type	Linear Trend Model
Data	Disk Drives
Length	5
NMissing	0

Fitted Trend Equation

Yt = 126.00 + 18.00×t

Accuracy Measures

MAPE	2.6455
MAD	4.8000
MSD	32.0000

Forecasts

Period	Forecast
6	234

steps for part d:-

statbasic statistics correlation in variables select year , disk drivesin method select Pearson correlationok.

you minitab output be:-

Correlation: Year, Disk Drives

Correlations

Pearson correlation	0.976
P-value	0.004

answer to the problem:-

	answer	explanation
a. Forecast the number of disk drives to be made next year, using trend analysis	234
b. Compute the mean squared error (MSE) when using linear regression.	32	we have MSD=32 we know, MSD=MSE
c. Compute the mean absolute percent error (MAPE).	2.65	MAPE=2.6455 2.65
d)i). What is the Correlation Coefficient?	98%	pearson correlation = 0.976 98%
ii). what does it tell you about the relationship between the independent variable an dependent variable?	"That there is a strong relationship"	high value of pearson correlation indicates that there is a strong relationship between year and disk drives.

***in case of doubt, comment below. And if u liked the solution, please like.