Analyzing Book Sales Data: Average Differences

This problem requires us to analyze the sales data provided in the table for four different book shops (A, B, C, and D), distinguishing between hardbound and paperback books. We need to calculate the difference between two specific averages.

Book Sales Data Table

Calculating Average Hardbound Books (Shops A, B, D)

First, let's find the average number of hardbound books sold by shops A, B, and D.

• Total hardbound books sold by shops A, B, and D = Sum of hardbound books sold by A, B, D.
• Total = $3500 + 3900 + 5500 = 12900$
• Number of shops considered = 3
• Average hardbound books = $\frac{\text{Total hardbound books}}{\text{Number of shops}}$
• Average hardbound books = $\frac{12900}{3} = 4300$

Calculating Average Paperback Books (Shops C, D)

Next, we calculate the average number of paperback books sold by shops C and D.

• Total paperback books sold by shops C and D = Sum of paperback books sold by C, D.
• Total = $5500 + 6600 = 12100$
• Number of shops considered = 2
• Average paperback books = $\frac{\text{Total paperback books}}{\text{Number of shops}}$
• Average paperback books = $\frac{12100}{2} = 6050$

Finding the Difference Between Averages

Finally, we need to find the difference between the average number of paperback books sold by C and D, and the average number of hardbound books sold by A, B, and D.

• Difference = (Average paperback books sold by C and D) - (Average hardbound books sold by A, B, and D)
• Difference = $6050 - 4300$
• Difference = $1750$

Therefore, the difference between the average number of paperback books sold by shops C and D and the average number of hardbound books sold by shops A, B, and D is 1750.