The demand of a product over 6 weeks is 90, 110, 105, 130, 85 and 102 per week. If the average of the last 3 weeks’ demand is x and that of the last 5 weeks is y, then x + y (correct to two decimal places) is :
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 212.07
The last 3 weeks are weeks 4, 5, 6 and the last 5 weeks are weeks 2 to 6:
\( \displaystyle x = \frac{130+85+102}{3} = \frac{317}{3} = 105.666\ldots \)
\( \displaystyle y = \frac{110+105+130+85+102}{5} = \frac{532}{5} = 106.4 \)
\(x+y = 212.066\ldots \approx 212.07\)