CH 6 AND 7

Question 1

Many continuous variables have distributions that are bell-shaped and are called

Answer 1

approximately normally distributed variables.

Question 2

The theoretical curve, called _____ can be used to study many variables that are not normally distributed but are approximately normal

Answer 2

Normal distribution curve

Question 3

The shape and position of the normal distribution curve depend on

Answer 3

Two parameters, mean and standard deviation

Question 4

T or F: Normal distribution Curve can be used to study many variables that are normally distributed but are not approximately normal

Answer 4

F

Question 5

What is the shape of normal distribution curve?

Answer 5

bell-shaped curve

Question 6

Are equal and located at the center of the distribution.

Answer 6

The mean, median, mode

Question 7

The normal distribution curve is what type of mode?

Answer 7

unimodal or single mode

Question 8

The curve is ______ about the mean.

Answer 8

symmetrical

Question 9

The curve is continuous or discontinuous

Answer 9

continuous

Question 10

The curve ________ touches the x-axis.

Answer 10

never

Question 11

The total area under the normal distribution curve is equal to

Answer 11

1

Question 12

The area under the normal curve that lies within one standard deviation of the mean is approximately

Answer 12

0.68 or 68%

Question 13

The area under the normal curve that lies within two standard deviations of the mean is approximately

Answer 13

0.95 or 95%

Question 14

The area under the normal curve that lies within three standard deviations of the mean is approximately

Answer 14

0.997 or 99.7%

Question 15

is a normal distribution with a mean of 0 and a standard deviation of 1.

Answer 15

standard normal distribution

Question 16

is a distribution obtained by using the means computed from random samples of a specific size taken from a population.

Answer 16

sampling distribution of sample means

Question 17

is the difference between the sample measure and the corresponding population measure due to the fact that the sample is not a perfect representation of the population.

Answer 17

sampling error

Question 18

The mean of the sample means will be ______ as the population mean.

Answer 18

same

Question 19

The standard deviation of the sample means _________ than the standard deviation of the population

Answer 19

will be smaller

Question 20

The standard deviation of the sample means is called

Answer 20

standard error of mean

Question 21

As the sample size n increases, the shape of the distribution of the sample means taken from a population with mean  and standard deviation of  will approach a normal distribution.

Answer 21

Central limit theorem

Question 22

can be used to answer questions about sample means in the same manner that the normal distribution can be used to answer questions about individual values

Answer 22

Central limit theorem

Question 23

T or F: normal distribution is often used to solve problems that involve the binomial distribution

Answer 23

T

Question 24

is a correction employed when a continuous distribution is used to approximate a discrete distribution.

Answer 24

Correction for continuity

Question 25

Is defined as a characteristic or attribute that can assume different values.

Answer 25

Variable

Question 26

A variable whose values are determined by chance

Answer 26

random variable

Question 27

A variable can assume only a specific number of values, such as the outcomes for the roll of a die or the outcomes for the toss of a coin

Answer 27

discrete variable

Question 28

A variable can assume all values in the interval between two given values then the variable

Answer 28

continuous variable

Question 29

consists of the values a random variable can assume and the corresponding probabilities of the values.

Answer 29

Probability distribution

Question 30

is found by multiplying the square of each outcome by its corresponding probability, summing these products, and subtracting the square of the mean

Answer 30

variance of a probability distribution

Question 31

The expected value of discrete random variable of the probability distribution is the theoretical average of the variable

Answer 31

expectation

Question 32

binomial experiment is a probability experiment that satisfies the following four requirements:

Answer 32

Each trial can have only two outcomes or or outcomes that can be reduced to two outcomes There must be a fixed number of trials. The outcomes of each trial must be independent of each other. The probability of success must remain the same for each trial.

Question 33

The outcomes of a binomial experiment and the corresponding probabilities of these outcomes

Answer 33

binomial distribution

Question 34

probability of a success

Answer 34

P(S)=p

Question 35

probability of failure

Answer 35

P(F) = 1-p=q