Given the dataset

We start by computing the average:

We compute the difference bewteen each element and the average:

We square those differences:

And take the average of those squared differences: we sum them

And we divide by the number of elements:

Finally, we take the square root of this quantity and we have the standard deviation:

Answer:
C is your answer for this question
1). The answer is 86. .29n =24.94
In order to obtain this you need to divide both sides by .29
2) The answer is 25%
35/140 x 100% =25%
3) The answer is $70
So if 100% of 40 is 40 and 75% of 40 is 30 than you need to add 40 + 30 which equals 70.
Hope this helps :)
Answer:
7 1/2 cups
Step-by-step explanation:
20 gallons is ten times 2 gallons.
Ten times the amount of water will require ten times the disinfectant (we assume).
... 10 × 3/4 cup = 30/4 cups = 7 1/2 cups