Q10. Bar Graphs
TITA · +3 / 0
How many buyers gave ratings on Day 1?
Correct Answer
150
Step-by-step solution
📌 Core Concept
Use the Day 2 bar chart to get the Day 2 total and sum of ratings, then use the Day 2 cumulative average to find the Day 1 count.
🔢 Step-by-Step Solution
1
Reading the chart, Day 2 has 5, 10, 5, 20 and 10 buyers giving ratings 1, 2, 3, 4 and 5. That is 50 buyers.
2
Sum of Day 2 ratings .
3
Let be the number of buyers on Day 1. The Day 1 average is 3, so the Day 1 sum is .
4
The cumulative average after Day 2 is 3.1, so .
5
Then , so and .
Quick Check
Day 1 sum is 450, so the two-day sum is 620 over 200 buyers, which is 3.1.
Correct Answer: 150