A group of 12 students has a mean height of 58 inches. Another group of 6 students has a mean height of 52 inches. What is the mean height of the 18 students? Explain how you found your answer.

56 inches  

Step-by-step explanation:

A weighted average must be made, that each average has an assigned weight and in this way a resulting average can be obtained.

That is, the average of 12 students has a weight of 12 and the average of 6 students has a weight of 6, and then divide by the total weight, that is, 18, like this:

(58*12 + 52*6) / 18 = 56

56 inches tall is the average of the 18 students

d. 8

step-by-step explanation:

the given radical expression is:

we can rewrite this as:

we express as square numbers to get;

the exponents will now cancel out to give.

the correct answer is d

2,160 π

step-by-step explanation: