We are given the data 4 8 5 12 3 9 5 2 and is asked for the mean and standard deviation of the numbers or data set. The mean is the average equal to 6. The standard deviation reveals the spread of the data. In this case, the standard deviation is equal to 3.16
5:8 is the ratio, pages:minutes. 5 is the amount of pages read, 8 is the minutes it took. 8 divided by 5 = 1.6 which would be the average time it took for him to read one page. A greater ratio would be anything higher than an average of 1.6 minutes per page.
75-5(2×6)
75-5×12×
-60×+75
First you can find

of 90.
90 x

= 62
Next, you have $62 left and spent

of it. Meaning you have

of 62 left.
62 x

= about <span>53.14285
</span>
As your answer is not a whole number, you could round according to whatever guidelines your homework has given you (for example - rounding to the 2nd decimal place $53.14)