From a Table
Find the probability that a randomly chosen student is a freshman.
0.2261
What do probability distributions have to add up to?
1
Sam gets a home run 3% of the time he is at bat. What is the chance that in 30 at bats, he gets at least 3 home runs?
0.06
Find the probability that a randomly chosen freshman plays video games.
0.6667
The probability of event C occurring is 0.6. What is the probability that C does not occur?
0.4
The probability of at least 8 successes in 12 trials given a probability of success of 45%.
What is DISTR (or 2nd VARS)--> 1-binomcdf(12,.45,7)?
Find the probability that a randomly chosen video game player is a freshman.
0.2609
What do we need to check before we can approximate a binomial situation with a Normal curve?
At least 10 expected successes and at least 10 failures (np > 10 and n(1-p) > 10)
Sam gets a home run 3% of the time he is at bat. What is the chance that in 30 at bats, he gets 4 or fewer home runs?
0.998
Are playing video games and being a freshman mutually exclusive? Explain.
no
What is the difference between geometric and binomial random variables?
Counting successes versus counting trials until success.
Sam gets a home run 3% of the time he is at bat. What is the chance that in 30 at bats, he gets exactly 1 home run?
0.372
Are playing video games and being a freshman independent? Explain.
no
When do you use cdf and when do you use pdf?
cdf = multiple values of X
pdf = one value
Sam gets a home run 3% of the time he is at bat. How many at bats can we expect before he gets a home run?
33.333