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

\( \frac{14 + 12 + 15 + 11}{4} \) = \( \frac{52}{4} \) = 13

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.

To take the square root of a fraction, break the fraction into two separate roots then calculate the square root of the numerator and denominator separately:

\( \sqrt{\frac{4}{25}} \)
\( \frac{\sqrt{4}}{\sqrt{25}} \)
\( \frac{\sqrt{2^2}}{\sqrt{5^2}} \)
\(\frac{2}{5}\)

The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:

\( \frac{7}{100} \) x 7 = \( \frac{7 \times 7}{100} \) = \( \frac{49}{100} \) = 0.49 errors per hour

So, in an average hour, the machine will produce 7 - 0.49 = 6.51 error free parts.

The machine ran for 24 - 2 = 22 hours yesterday so you would expect that 22 x 6.51 = 143.2 error free parts were produced yesterday.

To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so subtract the coefficients and retain the base and exponent:

4a⁷ - 6a⁷
(4 - 6)a⁷
-2a⁷