Answer:
simple forecast combination = 339.66
Step-by-step explanation:
given data
Mary sell = 316
Susan sell = 500
Sarah sell = 203
to find out
What would be the result of a simple forecast combination
solution
we get simple forecast combination will be express here as
simple forecast combination = ( Mary sell + Susan sell + Sarah sell ) รท 3 ....................1
put here value we get
simple forecast combination =

simple forecast combination = 339.66