If 7 items cost 10, 20, 30, 40, 50, 60, and 70 respectively, what is the average cost?

To find the average cost of the items, you first need to sum all the individual costs and then divide by the total number of items.

In this case, the costs of the items are 10, 20, 30, 40, 50, 60, and 70. Adding these values together gives:

10 + 20 + 30 + 40 + 50 + 60 + 70 = 280

Next, you divide the total cost by the number of items, which is 7:

280 ÷ 7 = 40

Thus, the average cost of the items is 40. This computation shows the correct answer is 40, which reflects the overall expenditure distributed evenly across all items, thereby providing you with a clear understanding of the concept of calculating averages in a straightforward manner.