Chapter 6

General

100

A variable that can only take on a countable number of distinct values

What is a discrete random variable?

200

Displays the possible values of a random variable X and how probabilities are assigned to those variables

What is a probability distribution?

300

Calculates the probability of the Yth trial being the first successful trial in a geometric setting.

What is geometpdf?

400

The three parameters needed to define a binomial distribution

What is number of trials, probability of success, and number of successes?

500

Description of the conditions for a binomial setting and geometric setting.

What is BINS (Binary - outcomes are success or failure, Independent - trials are independent, Number - fixed number of trials, Success - probability of success is the same on each trial)

What is BITS (same, same, Trials - count trials up to and including the first success, same)

Linear Transformations and Combinations

100

When adding a constant to a random variable do the mean and standard deviation change?

Only the mean

200

X = $ amount of each size soda (random variable)

meanx = 1.8

sdx = .7

Find the new mean and sd if the store increases their prices of soda by $1 each

2.8, .7

300

Let A and B be random variables

mean_A = 6.4

mean_B = 8.9

Find mean_A+B 

15.3

400

X and Y are Random Variables

sd_x = 8

sd_y = 7

Find sd_x-y

sqrt(113) = 10.63

500

Let U and V be random variables that are approximately normally distributed.  

mean_u = 500, sd_u = 15

mean_v = 200, sd_v = 8

Let T = U + V, find P(T > 717)

.16

Binomial/Geometric Calculations

100

The difference between binomial and geometric settings

fixed number of trials versus counting trials until the success

200

You take a 30 question multiple choice test (choices A-D for each question), and unfortunately know nothing on it.  If you were to guess on every question, what is the probability that you get 5 questions correct?

binomialpdf(30,.25,5)

.1047

300

Tim makes 80% of his free throws.  In a game, he takes 14 free throw attempts.  Find the mean and standard deviation of the distribution

mean = (.8)(14)

SD = sqrt(14x.8x.2)

400

You take a 30 question multiple choice test (choices A-D for each question), and unfortunately know nothing on it.  If you were to guess on every question, what is the probability that you get 5 or more questions correct?

1-binomialpdf(30,.25,4) = .93958

500

A wide receiver has a catch rate of 40%.  What is the probability that his first catch will be before his 3rd target?

geometriccdf(.4,2)