For the SAT nationally, the mean is 502 and the standard deviation is 101. If a school finds that the mean score is 470 from a random sample of 100 seniors, can they claim that they perform at the national average?

all of the measures need to be converted to the same measure; such as inches. if you do that it is easy to determine which is the longest, 2500 mm which is approximately 97.5 inches.

you would 18 *0.25 = 4.5

20/27

​​

step-by-step explanation:

1 simplify brackets

-\frac{8}{9}\times \frac{5}{6}−

​9

​

​8

​​ ×

​6

​

​5

​​

2 use this rule: \frac{a}{b}\times \frac{c}{d}=\frac{ac}{bd}

​b

​

​a

​​ ×

​d

​

​c

​​ =

​bd

​

​ac

​​

-\frac{8\times 5}{9\times 6}−

​9×6

​

​8×5

​​

3 simplify 8\times 58×5 to 4040

-\frac{40}{9\times 6}−

​9×6

​

​40

​​

4 simplify 9\times 69×6 to 5454

-\frac{40}{54}−

​54

​

​40

​​

5 simplify \frac{40}{54}

​54

​

​40

​​   to \frac{20}{27}

​27

​

​20

​​