quiz 6

Question 1

_________ random variables, such as heights and weights, length of life of a product, can assume the infinitely many values corresponding to points on a line interval

Answer 1

continuous

Question 2

The ______ under a continuous probability distribution is equal to 1

Answer 2

AREA

Question 3

The probability that x will fall into a particular interval, say from a to b, is equal to the ________between the 2 points

Answer 3

AREA UNDER THE CURVE

Question 4

P(x=a)=????

Answer 4

0, for continuous random variable

Question 5

This implies that P(x≥a) ? P(x>a) and
P(x≤a) ? P(x<a)

Answer 5

=

Question 6

the continuous _______ random variable is used to model the behavior of a random valuable whose values are uniformly or evenly distributed over a given interval

Answer 6

UNIFORM

Question 7

The total area under the probability distribution is 1/(b-a) X (b-a)=??

Answer 7

1

Question 8

The probability that x falls in an interval is calculated as the area under the _____ over that interval

Answer 8

CURVE

Question 9

The mean and variance of x for uniform random variable are given by…

Answer 9

ϻ= (b-a)/2 and σ²= 1/12 (b-a)²

Question 10

the_____ random variable is used to model positive random variables such as waiting time, or lifetime associated with electronic components

Answer 10

exponential

Question 11

the parameter λ is often referred to as the _______ and is related to the mean and the variance

Answer 11

intensity

Question 12

for exponential random variable, mean and variance are….

Answer 12

ϻ= 1/λ and σ²= 1/λ²
so that ϻ=σ (standard deviation)

Question 13

a large # of random variables observed in nature possess a frequency distribution that is approximately __________ and can be modeled by a ___________probability distribution

Answer 13

MOUND SHAPED, NORMAL

Question 14

The mean locates the ______ of the distribution and the distribution is ________ about its mean

Answer 14

center, symmetric

Question 15

The shape of the distribution is determined by _____, the population standard deviation

Answer 15

σ

Question 16

Notice the difference in shape and location. Large values of σ reduce the ______ of the curve and increase the ______, small values of σ increase the ______ and reduce the _______.

Answer 16

height, spread, height, spread

Question 17

The probability distribution for Z is called the ________ because its mean is 0 and its standard deviation is 1.

Answer 17

standard normal distribution

Question 18

z= (x-ϻ)/σ

Answer 18

turn normal random variable into standard normal

Question 19

for standard normal distribution, the area to the left of a value C is probability P(z<C)

Answer 19

yeah