Answer:
0.0274
Step-by-step explanation:
The mean is
and the standard deviation is 
Calculate
for 
If
then 
and

Use table for normal distribution probabilities to get that

I think this is the answer, sorry I am not 100% sure
Since P(<em>X</em> = <em>x</em>) = 0.3 for all 0 ≤ <em>x</em> ≤ <em>α</em>, we have

So,


Answer:
l = (S/pi)-r^2
Step-by-step explanation:
Just rearrange the equation.
S = pi*l + pi * r^2
S-pi*r^2 = pi*l
l = (S-pi*r^2)/pi
l = (S/pi)-r^2