# Mean & standard deviation

for part C),

I'm tempted to think this is a uniform distribution, though not quite sure, as there are two numbers, 50 and 80.

I'm also tempted to think this could be a normal distribution, where I try to build simultaneous equations using the Z-score equation, to solve for mean and standard deviation?

• You can use the fact that $Pr[A]=Pr[A|B]\cdot Pr[B] + Pr[A|\neg B]\cdot Pr[\neg B]$. For example $$Pr[C_B=50] = \overbrace{Pr[C_B=50|X\leq 1/2]}^{=1}\cdot Pr[X\leq 1/2] + \overbrace{Pr[C_B=50|X> 1/2]}^{=0}\cdot Pr[X> 1/2]$$ – Zubzub Apr 24 '17 at 11:41