The daily sales (in thousand Rs.) of a shop on nine consecutive days are 112, 124, 118, 126, 130, 150, 150, 119, 138. The 7-day moving averages are
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 130, 131, 133
Each 7-day moving average is the mean of seven consecutive days, placed against the middle (fourth) day of the seven. Nine days give 9 − 7 + 1 = 3 moving averages:
\( \displaystyle \text{Day 4}: \frac{112 + 124 + 118 + 126 + 130 + 150 + 150}{7} = \frac{910}{7} = 130 \)
\( \displaystyle \text{Day 5}: \frac{124 + 118 + 126 + 130 + 150 + 150 + 119}{7} = \frac{917}{7} = 131 \)
\( \displaystyle \text{Day 6}: \frac{118 + 126 + 130 + 150 + 150 + 119 + 138}{7} = \frac{931}{7} = 133 \)