you have 6 quarters, 10 dimes, 4 nickles, 2 pennies. One coin is selected at random. What is the expected value of this experiment?

Question

anonymous · Answer

multiply the amount you would get times the probability you get it, and add them up

anonymous · Answer

other way is to take the average of all the money, total the amount of money you have, divide by the total  number of coins
it is the same thing

rulnick · Answer

E[X] = (6/22) * 0.25 + (10/22) * 0.10 + (4/22) * 0.05 + (2/22) * 0.01.

rulnick · Answer

... value of E[X] is in dollars as expressed above.

anonymous · Answer

rulinck wrote first way. second way is 
$$\frac{6\times .25+10\times .1+4\times .05+2\times .01}{22}$$

anonymous · Answer

rounded to the nearest cents is .12.....is this correct?

rulnick · Answer

Yes!

rulnick · Answer

$0.123636 ... or about 12 cents.