Chapter 6 - Random Variables

Question 0

probability distribution

Answer 0

gives it’s possible values and their probabilities

Question 1

random variable

Answer 1

takes numerical values that describe the outcomes of a chance process

Question 2

discrete random variables

Answer 2

random variable that can take one of a finite number of distinct outcomes
“the number of…”

Question 3

mean (expected value) of discrete random variable

Answer 3

multiply each value by It’s probability then add all products

Question 4

continuous random variable

Answer 4

random variable that can take any numerical value within a range of values, the range may be infinite or bounded
“the amount of…”
measures something

Question 5

if y = a + bx is a linear transformation of the random variable x, then

Answer 5

-probability distribution of Y has the same shape as probability of x if b>0

Question 6

independent random variables

Answer 6

if x tells us nothing about y and vice verses

Question 7

center of linear transformation

Answer 7

mew y = bmewx

Question 8

spread of linear transformation

Answer 8

oy= |b|ox

Question 9

when we perform several independent trials of the same chance process & record the # of times a certain outcome occurs

Answer 9

binomial setting

BINS

Question 10

count of X successes in binomial setting

Answer 10

binomial random variable

Question 11

probability of distribution X with parameters n and p
n = number of trials
p = probability

Answer 11

binomial distribution

Question 12

use binompdf when

Answer 12

x = k

Question 13

use binomcdf when

Answer 13

x less than or equal to k

Question 14

mean of binomial random variable

Answer 14

mewx = np

Question 15

ox of binomial random variable

Answer 15

square root of np(1-p)

Question 16

geometric setting

Answer 16

perform independent trials of the same chance process and record # of trials it takes to get one success

Question 17

number of trials Y that it takes to get a success in a geometric setting

Answer 17

geometric random variable

Question 18

probability of Y with parameter p, probability of success on any trial

Answer 18

geometric distribution

Question 19

use geometpdf when

Answer 19

P(y=k)

Question 20

use geometcdf when

Answer 20

P(Y less than or equal to k)