20.75 because if you add 4.85+7.95+7.95 add that you get 20.75
Tan (0) is equal to 0
Sin (0) = 0
Cos (0) = 1
Tan = Sin/Cos
That means that Tan (0) = 0/1 or 0
1) Mean
The mean is given by the sum of the data divided by the number of data (4, in this case):

2) Standard deviation
The standard deviation is given by:

where

is the mean, that we already found at point 1), and N=4. Substituting data, we have:

The domain of the function is (-1,0,1,2,3,4,5)
for the graph the domain is (-∞,<span>∞</span>)