Vocab
Discrete + Continuous
Geometric + Poisson
Binomial Probability
Expected Value
100
What is a finite or countable # of possible outcomes that can be listed?
discrete random variable
100
x represents the distance from the earth to the moon
Continuous
100
The probability of an enemy aircraft penetrating friendly airspace is 0.01. What's the probability that the first penetration of friendly airspace is accomplished by the 80th aircraft to attempt the penetration of friendly aircraft?
P(80,0.01)= 0.01(1-0.01)^80-1 = .00452
100
Which fraction represents the probability of obtaining exactly 8 heads in 10 tosses of a fair coin?
45/1024
100
The expected value of a discrete random variable is equal to the ______ of the random variable?
mean
200
What is an uncountable # of outcomes represented by an interval on a number line?
continuous
200
x represents the number of rainy days in the month of September in New York
Discrete
200
A complex software system averages 7 errors per 5,000 lines of code. What is the probability of exactly 2 errors in 5,000 lines of randomly selected code?
P(2,7)= (e^-7)(7^2) / 2! = 0.022
200
If a fair die is tossed 5 times, what is the probability of getting exactly 3 even numbers?
10/32
200
In a lottery, 10,000 tickets are sold at $2 with a prize of $5,000 for one winner. What can you expect to gain from buying one ticket?
$-1.50
300
What does n, p, q, and x represent?
n= number of trials x= the number of successes in n trials p=probability of success in a single trial q= probability of failure in a single trial
300
x represents the amount of money you make each week
discrete
300
A cereal maker places a game piece in it's cereal box. The probability of winning a prize is 1 in 4. What is the probability that you win your first prize within your fourth box of cereal?
P(4)= (1/4)(3/4)^3 = .10546875
300
25% of unicorns like celery. You randomly select 18 unicorns to name their favorite vegetable. Find the probability that 4 unicorns say they like celery.
.2129801598
300
Concessionaires know that attendance at a football stadium will be 10,000 on a clear day, 5,000 if there is light snow, and 3,000 if there is heavy snow. The probability of clear skies, light snow, or heavy snow on any particular day is .7, .25, and .05 respectively. What average attendance should be expected for the season?
8,400 people
400
What is a numerical value associated with each outcome of a probability experiment?
Random Variable
400
x represents the length of time it takes to get home from school
continuous
400
Over a long period of time, it has been noted that on Friday's 25% of customers at the drive in window at the bank make deposits. What's the probability that it takes 4 customers at the drive-in window before the first one makes a deposit.
P(4)= (.75)^4-1 (.25) = .0117
400
60% of mermaids want to be human. If you interview 7 mermaids, what is the probability that less than 2 want to be human?
.0188416
400
At a raffle, 1,000 tickets are sold at $1 each for two prizes of $400 and $200. You buy one ticket. What is the expected value of your gain?
$-00.40
500
What lists each possible value the random variable can assume together with it's probability?
Discrete Probability Distribution
500
x represents the acceleration of a car as it goes from 0 mph to 60 mph
continuous
500
The mean number of accidents per month at an intersection is 3. What's the probability that in any given month more than 2 accidents will occur?
poissionpdf(3,2) + poissonpdf(3,1) + poissonpdf(3,0) = .4231900811 1- .4231900811 = .5768099189
500
25% of unicorns like celery. You randomly select 18 unicorns to name their favorite vegetable. Find the probability that less than 4 unicorns say they like celery.
.305689170
500
Your father offers to flip a coin once and if the coin lands on heads he will give you $50, but if it lands on tails you will get nothing. Your mother offers to roll a die one time and give you $5 for each spot that turns up. Which of these is the better offer?
Your father's offer is better. It has an expected value of $25, while your mothers offer only has an expected value of $17.50.
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