Vocabulary
Chapter 6 is all about this topic...
Random Variables
Please write out the general equation for finding
P(X = x) in a Binomial RV setting
P(X = x) = (nCx)*(p)^x *(1-p)^(n-x)
Find the expected value of the following Discrete RV:
x 0 | 1 | 2
P(x) .2 | .4 | .4
What is 0 + .4 + .8 = 1.2
Who is the artist for Mr. Cardenas' guilty pleasure song from back in high school?
Who is Rihanna?
The theoretical, long-run, Expected Value of a random variable if we keep running trials for a very long time.
Mean (μ )
What is the following formula used for in a Discrete Random Variable setting?
Sigmax*p(x)
The mean / expected value.
Find the standard deviation of the following Discrete RV:
x 0 | 1 | 2
P(x) .2 | .4 | .4
What is SD^2 = (0-1.2)^2(.2) + (1-1.2)^2(.4) + (2-1.2)^2(.4) SD^2 = .56 SD = .748
Hollister receives a new order of shirts each month. They receive 5 more shirts than the previous month each time. Would this data be discrete or continuous?
Discrete.
How old am I turning this year?
I'm turning 30
BE NICE TO ME ABOUT IT >:(
A probability distribution for a Random Variable X, where values of X can contain whole number and decimal values.
Continuous Random Variable.
what does a random variable "X" represent in a Geometric RV setting?
The trial number where the first (and only) success occurs.
In a Geometric setting, given the P(success) = .45
What is the expected value of the probability distribution?
What is mean: 2.22222
Mark refills his pool each day. He puts gallons of water in each day, adding two gallons more each day. He wants to keep a graph of how many gallons he puts in each day. Is this data discrete or continuous?
Continuous.
The title of the most popular segment in Mr. Cardenas's Team Builder Trivia activities.
(MAJOR throwback to week 1 of Stats)
"On The Tip of My Tongue" (OTTMT)
A probability distribution for a Random Variable X, where values of X contain whole number values exclusively.
Discrete Random Variable.
Please write out the general equation for finding
P(X = x) in a Binomial RV setting
P(X=x) = (1-p)^(x-1) *p
In a recent Pew study, it was found that 28% of all homes have at least one dog. Let X = the number of houses you look at before finding a house with a dog. Find the probability you find the first a house with a dog on the 3rd house.
P(X=3) = (1-0.28)^(3-1) *0.28
= 0.145152 (14.52%)
Suppose we shuffle a standard deck of cards, and we turn over the top card. We put the card back in the deck and reshuffle. We repeat this process until we get a Jack.
Geometric
What university did Mr. Cardenas go to?
Cal State Long Beach?
A random variable defined by the acronym:
B.I.N.S.
Binomial Random Variable
What does this notation stand for,
mu(x)
What is the mean (expected value) of a random variable.
The Internal Revenue Service estimates that 20% of all taxpayers filling out forms make mistakes. An IRS employee randomly selects and checks 30 forms for mistakes. It is safe to assume that each form checked is independent.
What is the probability that exactly nine forms have an error?
P(X = 9) = (30C9)*(.2)^9 *(1-.2)^(30-9)
= 0.06756 (6.76%)
Mr. Cardenas notices a certain student shows up late to class 60% of the time. For the entirety of the third quarter, he records how many times they were late to class (it's called taking attendance, btw). This study lasted over the course of 30 class meetings.
Binomial
How many sisters do I have?
Three