To find the average of these 4 numbers add them together then divide by 4:

\( \frac{11 + 7 + 12 + 6}{4} \) = \( \frac{36}{4} \) = 9

A factorial has the form n! and is the product of the integer (n) and all the positive integers below it. For example, 5! = 5 x 4 x 3 x 2 x 1 = 120.

The amount of flour you need is (2\(\frac{5}{8}\) - 1\(\frac{3}{8}\)) cups. Rewrite the quantities so they share a common denominator and subtract:

(\( \frac{21}{8} \) - \( \frac{11}{8} \)) cups
\( \frac{10}{8} \) cups
1\(\frac{1}{4}\) cups

To subtract these radicals together their radicands must be the same:

6\( \sqrt{12} \) - 2\( \sqrt{3} \)
6\( \sqrt{4 \times 3} \) - 2\( \sqrt{3} \)
6\( \sqrt{2^2 \times 3} \) - 2\( \sqrt{3} \)
(6)(2)\( \sqrt{3} \) - 2\( \sqrt{3} \)
12\( \sqrt{3} \) - 2\( \sqrt{3} \)

Now that the radicands are identical, you can subtract them:

In order to find how many additional workers are needed to staff the extra crews you first need to calculate how many workers are on a crew. There are 12 workers at the company now and that's enough to staff 3 crews so there are \( \frac{12}{3} \) = 4 workers on a crew. 6 crews are needed for the busy season which, at 4 workers per crew, means that the roofing company will need 6 x 4 = 24 total workers to staff the crews during the busy season. The company already employs 12 workers so they need to add 24 - 12 = 12 new staff for the busy season.