Answer:
f(2) = 0 and f(6) = -4
Step-by-step explanation:
First, find f(x) when x = 2
Plug in 2 as x in the function:
f(x) = -(x - 2)
f(2) = -(2 - 2)
f(2) = -(0)
f(2) = 0
Next, find f(x) when x = 6. Plug in 6 as x in the function:
f(x) = -(x - 2)
f(6) = -(6 - 2)
f(6) = -(4)
f(6) = -4
So, f(2) = 0 and f(6) = -4
If the mean is 20.8, one standard deviation each way is adding and subtracting 3.1, so 17.7 and 23.9 (68% of values)
Two standard deviations adding and subtracting 3.1*2 = 6.2, or 14.6 and 27.
Three standard deviations is 11.5 and 30.1
So we have
11.5 - 14.6 - 17.7 - 20.8 - 23.9 - 27 - 30.1
Going left to 11.5 is 3 standard deviations out, so 99.7/2 = 49.85%
Going right to 27 is 2 standard deviations out, so 95/2 = 47.5%
Add those two % to get 97.32%
This is hard to do without a picture so I hope that helps!