Stat Final

Front 1

The t distribution always has n degrees of freedom

Back 1

False

Front 2

When the margin of error is added to and subtracted from the sample mean, an interval formed that will contain a probability of

Back 2

True

Front 3

Assuming the same level of significance a, as the sample size increases, the value of t a/2 approaches the value of z a /2

Back 3

True

Front 4

The exact spread of the distribution depends on the

Back 4

Number of degree of freedom

Front 5

The exact spread of the distribution depends on the

Back 5

Number of degree of freedom

Front 6

The t distribution approaches the distribution as the sample size

Back 6

Z, increases

Front 7

The exact spread of the distribution depends on the

Back 7

Number of degree of freedom

Front 8

The t distribution approaches the distribution as the sample size

Back 8

Z, increases

Front 9

The width of a confidence interval will be

Back 9

narrower for 90 percent confidence than for percent confidence.

Front 10

The exact spread of the distribution depends on the

Back 10

Number of degree of freedom

Front 11

The t distribution approaches the distribution as the sample size

Back 11

Z, increases

Front 12

The width of a confidence interval will be

Back 12

narrower for 90 percent confidence than for percent confidence.

Front 13

As standard deviation increases , sample size to achieve a specified level of confidence

Back 13

Increases

Front 14

The exact spread of the distribution depends on the

Back 14

Number of degree of freedom

Front 15

The t distribution approaches the distribution as the sample size

Back 15

Z, increases

Front 16

The width of a confidence interval will be

Back 16

narrower for 90 percent confidence than for percent confidence.

Front 17

As standard deviation increases , sample size to achieve a specified level of confidence

Back 17

Increases

Front 18

When determining the sample size If the value found not an integer you shouldchoose the highest Integer value

Back 18

Always

Front 19

When constructing a confidence interval for a population mean, if a population is normally distributed and a small sample is taken then the distribution of X base

Back 19

T distribution

Front 20

When constructing a confidence interval for a population mean, if a population is normally distributed and a small sample is taken then the distribution of X base

Back 20

T distribution

Front 21

When the sample size and the proportion prematn the same, a percent confidence the 99 for

Back 21

narrow than

Front 22

The manager of the department for a manufacturing company wants the average strength of rubber used certain brand of standard deviation is known She z test to test the null hypothesis that the meani strength is less than or equal to 800 pounds per square inchThe calculate for the test. If the significance level for this test is 10the null hypothesis would be rejected

Back 22

True

Front 23

A Type error is rejecting a true null hypothesis.

Back 23

True

Front 24

The larger the pvaluethe more we doubt the null hypothesis

Back 24

False

Front 25

A Type error falling to reject a false null hypothesis.

Back 25

True

Front 26

A Type error falling to reject a false null hypothesis.

Back 26

True

Front 27

the for a population proportion or meanIf level of significance is less than the p value, the null hypothesis is rejected

Back 27

False

Front 28

When testing a hypothesis about a single meanIf the sample size is 51 and the population standard deviation is known, the correct test statistic to

Back 28

Z

Front 29

When testing a hypothesis about a single meanIf the sample size is 51 and the population standard deviation is known, the correct test statistic to

Back 29

Z

Front 30

For a fixed sample size, the lower we athe higher is the

Back 30

Type ll error

Front 31

When testing a hypothesis about a single meanIf the sample size is 51 and the population standard deviation is known, the correct test statistic to

Back 31

Z

Front 32

For a fixed sample size, the lower we athe higher is the

Back 32

Type ll error

Front 33

As Type errorof statistical tost increases the power of the

Back 33

Decreases

Front 34

Assuming that the null hypothesis the the of a of the stand that as extreme as the valise computed from the sample

Back 34

P- Value

Front 35

What is the degrees of freedom for the t-test of two independent population means when we assume equal variances? Let n1 be the sample size of the first population and n2 be the sample size of the second population.

Back 35

n1+n2 -2

Front 36

Which of the following samples are paired? Select all that apply

Back 36

Compare the effect of a new drug from 10 patients who has measurements before and after taking this new drug.

40 students attend a training program. Their pre-traing test scores and post-training test scores were compared

Front 37

To test if the two independent population have equal variances, we use

Back 37

F test

Front 38

What was the trick that I shared with you in the step of calculating the test statistics F^ +

Back 38

always assign subscription 1 to the sample with larger sample variance

Front 39

The F distribution is

Back 39

Skewed to the right

Front 40

F-distribution has two parameters: numerator degrees of freedom and denominator degrees of freedom.

Back 40

True

Front 41

What is the TOTAL sample size of the example given in this video?

Back 41

800

Front 42

When the sample size is large, what distribution can we assume for the sample proportion?

Back 42

Normal distribution

Front 43

an inependent samples expertment an experiment in which there is no relationship between the measurements in the different samples

Back 43

True

Front 44

an inependent samples expertment an experiment in which there is no relationship between the measurements in the different samples

Back 44

True

Front 45

in forming a confidence interval for mu 1 - mu 2 only two assumptions are required independent samples and sample sizes of at least 30

Back 45

False

Front 46

an inependent samples expertment an experiment in which there is no relationship between the measurements in the different samples

Back 46

True

Front 47

in forming a confidence interval for mu 1 - mu 2 only two assumptions are required independent samples and sample sizes of at least 30

Back 47

False

Front 48

an experiment involving matched pairsa sample of 12 pairs of observations is collectedThe degrees of freedom for the statistic 10

Back 48

False

Front 49

an inependent samples expertment an experiment in which there is no relationship between the measurements in the different samples

Back 49

True

Front 50

in forming a confidence interval for mu 1 - mu 2 only two assumptions are required independent samples and sample sizes of at least 30

Back 50

False

Front 51

an experiment involving matched pairsa sample of 12 pairs of observations is collectedThe degrees of freedom for the statistic 10

Back 51

False

Front 52

When comparing two Independent population means, n 1 =13 and n 2 =10, degrees of freedom for the 22

Back 52

False

Front 53

an inependent samples expertment an experiment in which there is no relationship between the measurements in the different samples

Back 53

True

Front 54

in forming a confidence interval for mu 1 - mu 2 only two assumptions are required independent samples and sample sizes of at least 30

Back 54

False

Front 55

an experiment involving matched pairsa sample of 12 pairs of observations is collectedThe degrees of freedom for the statistic 10

Back 55

False

Front 56

When comparing two Independent population means, n 1 =13 and n 2 =10, degrees of freedom for the 22

Back 56

False

Front 57

There are two types of machines, called type A and type B. Both type A and type B can be used to produce a certain product machines. He assigns each of the 15 workers to both types of machines to compare their hourly production rate. In other hour each . These two samples are mdependent

Back 57

False

Front 58

In testing for the equality of means from two wdependent populations. the hypothesis of equal populamon means is rejected

Back 58

Always

Front 59

In testing for the equality of means from two wdependent populations. the hypothesis of equal populamon means is rejected

Back 59

Always

Front 60

A new company is the process of evaluating its customer service. The company offers two types of sales: (1) Internet sale that the Intemet sales are more than 10 percent higher than store sales. The null hypothesis would be

Back 60

PIternet - p s -P store <=.18 .

Front 61

In order to test the effectiveness of a drug called designed to reduce cholesterol levels the cholesterol levels of heart patients are measured before they are given the same 9 patients use XZR for two continuous months. After two months of usethe cholesterol levels are measured again the comparison of atterthe drug an example of testing the difference between

Back 61

matched pairs from two dependent populations

Front 62

In testing the difference between the means of two normally distributed populations using Independent random sam

Back 62

t statistic

Front 63

When testing the difference between two population proportions using large independent random samples, the

Back 63

Z

Front 64

A financial analyst working for a financial consulting company wishes to find evidence that the average price earnings ratio In the banking Industry. The alternative hypothesis is

Back 64

u consumer > u banking

Front 65

it we are testing the hypothesis about the mean of a population differences with samples of n 1 =10n 2 =10, degrees of freedom for the statistics

Back 65

9

Front 66

A simple linear regression model is to study the relationship between

Back 66

two continuous random variables

Front 67

Which of the following is a point estimate of the slope of the simple linear regression?

Back 67

b1

Front 68

r ^ 2 model 1 and 2 is 0.91 and 0.74, respectively, which model has a better fit?

Back 68

Model 1

Front 69

In the scatter plot of y vs x, if you see y decreases with the increase of x, what you can tell about the correlation coefficient ? (r)

Back 69

r<0

Front 70

In the scatter plot of y vs x, if you see y decreases with the increase of x, what you can tell about the correlation coefficient ? (r)

Back 70

r<0

Front 71

What are the assumptions for the error term in the simple linear regression? Check all that apply .

Back 71

Zero mean Normality Constant variance Independence

Front 72

In the simple linear regression , what is the degrees of freedom of SSE? Let's denote n fo the sample size .

Back 72

n-2

Front 73

In the simple linear regression , what is the degrees of freedom of SSE? Let's denote n fo the sample size .

Back 73

t test

Front 74

What is the number of degrees of freedom for the test of significance of the slope and y intercept in a simple linear regression model?

Back 74

n-2

Front 75

The dependent variable is the variable that is being described or predicted

Back 75

True

Front 76

the difference between an Individual value of the dependent variable and the corresponding mean va

Back 76

False

Front 77

A simple linear regression model is an equation that describes the stralght-line relationship between a dependent variable and an independent variable

Back 77

True

Front 78

The residual is the difference between the observed value of the dependent varlable and the predicted value of the dependent variable

Back 78

True

Front 79

In a simple linear regression analysis, the correlation coefficient () and the slope (b)\ \ have the same sign

Back 79

Always

Front 80

All of the following are assumptions of the error terms the simple linear regression model except

Back 80

error tems are dependent on each other

Front 81

Themeasures the strength of the linear relationship between the dependent variable and the independent variable

Back 81

Correlation coefficient

Front 82

The least squares regression line minimizes the sum of the

Back 82

squared differences between actual and predicted Y values