Final answer:
The mean of the T-shirt prices (8, 10, 10, 12, 15, 15, 18) is found by adding the prices and dividing by 7, resulting in a mean of 12.57.
Step-by-step explanation:
The question involves finding the mean of a set of numbers, which represent the prices of T-shirts. The mean is a measure of central tendency that is calculated by adding all the values in the set and then dividing the sum by the number of values.
The prices of the T-shirts listed are 8, 10, 10, 12, 15, 15, and 18. To find the mean, you would first add these prices: 8 + 10 + 10 + 12 + 15 + 15 + 18 = 88. Then you divide this sum by the number of T-shirts, which is 7. So, the mean price is 88 divided by 7, which equals 12.57.
The correct statement that best describes the mean of this set is 'the sum of the prices divided by 7'. This provides the average cost of the T-shirts in the store.