Question

A manager of a store that sells and installs spas wants to prepare a forecast for January, February, and March of next year. Her forecasts are a combination of trend and seasonality. She uses the following equation to estimate the trend component of monthly demand: Ft = 90 + 6t, where t = 0 in June of last year. Seasonal relatives are 1.07 for January, .88 for February, and .96 for March. What demands should she predict? (Round your answers to 2 decimal places.)

Answer 1

JANUARY = 218.28

FEBRUARY = 184.8

MARCH = 207.36

Step-by-step explanation:

Trend component of demand equation :

Ft = 90 + 6t, where t = 0 in June of last year

Seasonal relatives are ;

1.07 for January

0.88 for February

0.96 for March

Forecast for January, February and March of next year:

JANUARY :

last year June, 't' = 0,

[last year - this year - next year]

Therefore January of next year, 't' = 19

Ft = 90 + 6(19) = 204

Forecast = Ft × seasonal relative

Forecast = 204 × 1.07 = 218.28

FEBRUARY :

Therefore January of next year, 't' = 20

Ft = 90 + 6(20) = 210

Forecast = Ft × seasonal relative

Forecast = 210 × 0.88 = 184.8

MARCH:

Therefore January of next year, 't' = 21

Ft = 90 + 6(21) = 216

Forecast = Ft × seasonal relative

Forecast = 216 × 0.96 = 207.36