Janie asked:
I’m really struggling with these questions…getting the answer would be awesome but I would really like to know how to get there as well…I’m going to have an exam on this, nooooo!
1. In 4-spot Keno, you pick 4 numbers out of 80. If all 4 come up, you win $120. If 3 of your 4 come up, you win $4. If 2 come up, you win $1, with 1 or 0 numbers giving no prize. Let X be the winnings from a game of 4-spot Keno. The probabilities of each outcome can be obtained from the hypergeometric distribution and are as follows:
x; P(X = x)
$0; 234407/316316
$1; 67260/316316
$4; 13680/316316
$120; 969/316316
The amount you would expect to win from a game of 4-spot Keno is
2. Suppose 5% of the population has O-negative blood type, making them universal blood donors. If 15 people come to donate blood (a random sample from the population), the probability that at least 2 will be universal donors is
3. The weights of lemons in a large crate have a Normal distribution with μ = 137 grams and σ = 4.1 grams. Consider the random process of picking three lemons independently and putting them in a bag. The standard deviation of the total weight of the three lemons in the bag is (in grams)
One Comment on "Please I need a math genius to help with probability questions! Going mad?"
E(x) = xi * P(x = xi)
= 0*234407/316316+ 1*67260/316316 + 4*13680/316316+120*969/316316
= (0+67260+ 54720 +116280) /316316
238260/316316
= .75
2) n = 15 r = 2 p = 0.05 q = 0.95
15C2 p^2 q^13
3) μ = 137 σ = 4.1
standard deviation should be 4.1 not so sure