UNIT 4 P2 STATS

BINS

100

What does B stand for in BINS and what does it mean?

B in Bins stands for Binary and it means that there are only two possible outcomes

200

What does BINS mean? (list each letter)

B= Binary I= Independent N= Number S= Success

300

What is the Mean and Standard deviation equations?

(answer on cheat sheet)

400

How do we obtain probability values?

Menu —> Probability —> Distribution —> Geometric pdf of Geometric cdf

500

Shuffle a deck of cards, turn over the top card, and put back the card you pull out every-time, continue until you get an Ace

B= Ace or Not I= Replace Cards N= No # of trials decided ahead of time 

(NOT BINOMIAL)

BITS

100

What does the T stand for in BITS and what does it mean?

T= Trials, # of trials til success

200

What does B stand for in BITS and what does it mean

B stands for Binary and it means there are only 2 outcomes (success and failure)

300

When do we use Geometric Pdf? Geometric Cdf?

pdf = equality cdf = inequality

400

How to we calculate the mean (expected) value of a geometric random variable?

M_x = 1/p

500

Find the probability that a person receives a score lower than 10 with a probability of 1/7 being right?

p= 1/7 

P(x<10)=GeometricCdf (1/7, 0, 9) = .750

Find the expected value (mean) = M_x = 1/p = 1/1/7 = 7

DISCRETE RANDOM VARIABLE

100

What does Random Variable mean?

The numerical values that describes the outcomes of some chance process

200

What does probability Distribution mean?

The possible values and their probabilities. 

300

What are the two requirements that p must sastify?

Every probability p, is a number between 0 and 1

The sum of the probability is 1.

400

How can you find the mean of X?

(assume x is a discrete random variable w a prob. distribution)

u_x = E(X) = x₁p₁ + x₂p₂ + …. = E_xp₁

500

Consider the graph of the probability distribution of X and a seperate graph of the distribution of Y. How would the shapes compare?

Shapes will be the same 

Equations

100

How do you explain the meaning of P(x=2)

Probability of x being EXACTLY equal to p

200

How do you explain the meaning of P(x<7)

probability of x being lower than 7

300

How do you fine the mean for this problem?

Value of X:    0    1     2  

Probability: .02  .10  .20  

u_x = E(x) = 0(.02) + 1(.10) + 2(.20). = .5

example in sentence stem: we expect a students score to be between a 0 and 1

400

What does meaning of P(x >= 3)?

Whats the probability of a student getting above or below 3?

500

Shuffle a deck of cards, turn over the first 10 cards, one at a time. Let Y= the number of aces you observe. Is it binomial? Justify why.

hint: use BINS

B= ace or not (YES)

I= no replacement of cards (NO)

NOT BINOMIAL 

Symbols

100

What is the symbol for mean?

u

200

What is the standard deviation symbol?

(look on cheat sheet)

300

What does p stand for?

probability

400

What does x stand for?

value

500

What does P(x<2) stand for?

Probability of x being below two