North Dakota Electricc Company estimates its demand trend li

North Dakota Electricc Company estimates it\'s demand trend line (in millions of kilowatt hours) to be

D=77.0 + 0.45Q,

Where Q refers to the sequential quarter number and Q = 1 for winter of year 1. In addition, the multiplicative seasonal factors are as follows:

In year 26 (quarters 101-104), the energy use for each of the quarters beginning with winter is ___ (round your response to 1 decimal place)

Solution

As given in question, de-seasonalized demand formula:

D=77.0 + 0.45Q

Where, Q refers to the sequential quarter.

For year 26, there will be four quarters:

Winter – 101; spring – 102; summer – 103 & fall – 104

For quarter number 101,

D = 77+0.45*101 = 122.45

Multiplying it with the seasonal factor (index) 0.72 for winter -

Actual forecast = 122.45*0.72 = 88.164

= 88.2 millions of KWh