X 22 24 25 30 33 37
P(X) 0.16 0.09 0.18 0.12 0.24 0.21
What is the mean of this discrete random variable? That is, what is E(X), the expected value of X?

Question

X	22	24	25	30	33	37
P(X)	0.16	0.09	0.18	0.12	0.24	0.21
What is the mean of this discrete random variable? That is, what is E(X), the expected value of X?

amistre64 · Answer

this would be a weighted average right?

amistre64 · Answer

0.16	
0.09	
0.18	
0.12	
0.24	
0.21
-----
1.00

anonymous · Answer

i think so

amistre64 · Answer

multiply each X by its P(X) and add up the results; then divide by .... cant remember.  Sum of the Xs or sum of the P(x)s

anonymous · Answer

so 1 is not the answer

amistre64 · Answer

no, 1 aint the answer ... its the sum of the products of X*P(X)

amistre64 · Answer

E(X)=22(.16)+24(.09)+25(.18)+30(.12)+33(.24)+37(.21)

directrix · Answer

^^Continuing from above,
22(.16)+24(.09)+25(.18)+30(.12)+33(.24)+37(.21) = 29.47

amistre64 · Answer

lol, well, I was hoping trollz had enough wherewithal to deduce that part :)

anonymous · Answer

ok i c the answer thanks