Answer:
Goal = 45 (expected mean per week)
Ice creams sold each day = 54,45,33,39,48,40,21
Total Ice creams sold = 54+45+33+39+48+40+21 = 280
Total number of observations = 7
Mean = Total sum/total number of observation
= 280/7 (on simplification) = 40
Expected goal = 45
Mean of ice creams actually sold = 40
More ice creams to sell = Expected goal - Mean of ice creams actually sold
(on substituting the values)
= 45-40
= 5
Thus , the answer is option D , which is 5.