# Math Help - Data questions, answers?

1) hockey goaltender has a save percentage of 0.920. This means that the probability of any single shot taken on the goaltender being a goal is 0.08, What would be the expected number of goals scored on this goaltender in a game where she faced 35 shots?

2) a shopper chooses 2 LAN cables from a display of 20 cables that is known to contain 3 defective cables. Prepare a probability distribution for the random variable X that represents the number of defect cables in the shoppers purchase

3)A game involves rolling an octahedral die for each roll. The player wins half the dollar value of the number showing on the face if it is even. What price per play should be charged to make this a fair game?

4) A manufacturer of halogen bulbs knows that 3% of the production of their 100W bulbs will be defective. What is the probability that exactly 5 bulbs in a carton of 144 bulbs will be defective?

5) A student writes a 5 question multiple choice quiz. Each question has 4 possible responses. The student guesses at random for each question. Calculate probability for each possible score on the test from 0-5

6)A committee of 4 students will be selected from a list that contains 6 grade 9 students and 8 grade 10. What is the expected number of grade 10's on the committee?

7) A fair dice has 4 faces numbered 1-4. What is the probability of rolling a 2 exactly 3 times in 10 rolls of the die?

8) A player has a batting average of 0.350. What is the Expected value for his number of hits in a game with 6 at bats to the probability of the number of hits he is most likely to get?

2. Originally Posted by jessflan
1) hockey goaltender has a save percentage of 0.920. This means that the probability of any single shot taken on the goaltender being a goal is 0.08, What would be the expected number of goals scored on this goaltender in a game where she faced 35 shots?
$E(X) = n\times p$ where $n = 35 , p = .08$

you can take it from here?

3. ## Re: Data

Yeah, i can do that one, thank you!

can you help with any others?

4. Originally Posted by jessflan

8) A player has a batting average of 0.350. What is the Expected value for his number of hits in a game with 6 at bats to the probability of the number of hits he is most likely to get?
This one is similar to the first where

$E(X) = n\times p$

In this case $E(X) = 0.350, n= 6$

Can you find p?