General 3

Question 1

Marginal effect =

Answer 1

b1*2b2

Question 2

marginal effect or Top of sahmi or maximum point

Answer 2

B1/ 2b2.

Question 3

A logarithmic scale

Answer 3

is nearer to linear

Question 4

T statistics in regression analysis:

Answer 4

b1 – B1/sb1 in fact: b1/sb1

Question 5

Sb1=

Answer 5

the square root of MS error / SSx

Question 6

Interaction term,

Answer 6

The product of two variables in regression x1 and x2 incorporate the effect of the x2 variable when the variable x1 affects the relationship.

Question 7

In regression with multiple dummy variables, what is the most probable relationship?

Answer 7

Parabolic

Question 8

Dummy variable TRAP,

Answer 8

Is it impossible to model to tease out whether the effect comes from x1 or come from x2?

Question 9

Always dummy variables can be

Answer 9

divided into subdivisions that could impact the significance of other variables.

Question 10

If the dummy variable equal to 1 =

Answer 10

there is x amount more or less NOT one-unit decrease or increase and etc. in fact the dummy variable coefficient moves whole of regression line up or done according to y-axis NOT slope!

Question 11

Dummy variable use when

Answer 11

the x variable consists of multiple levels or is represent a nonlinear relationship,

Question 12

To move the parabola from the y-axis because of the y=x2 draw at the center of the y-axis!

Answer 12

So add another repetitive without power variable to move the parabola from the y-axis. So the parabola base not on the y axis in the regression equation.

Question 13

یک تابع گویا در ریاضیات، تابعی است که به صورت کسر قابل بیان است

Answer 13

برای نشان دادن رابطه بین دو متغیر رگرسیون وقتی یکی از ضرایب کسری یا معکوس شده باشد. Asymptotic nam dard ke bayangare shekle monhani ast

Question 14

The overall significance of the regression equation NOT occured

Answer 14

slope parameters are jointly zero.

Question 15

Overall significance of regression model determines

Answer 15

f-test and individual significance determined by t-test.

Question 16

F-statistics more than f-critical value:

Answer 16

Reject the null hypothesis.

Question 17

K is

and n-k-1 is

Answer 17

the horizontal top at the table

the vertical line of the f table.

Question 18

For the f test, we need

Answer 18

two degrees of freedom the first is k and the second is n-k-1.

Question 19

F critical value:

Answer 19

From the table with two degrees of freedom

Question 20

F-statistics 1 =

Answer 20

MSR / MSE

Question 21

F-statistics2 =

Answer 21

(R^2⁄(k-1))⁄((1-R^2)⁄(n-k))

Question 22

95 percent confidence interval=

Answer 22

95 percent of the area under the curve is between x and y.

Question 23

Using a 5 percent probability means that

Answer 23

There is a 5 percent probability of incorrectly rejecting the null hypothesis and it is acceptable.

Question 24

P-value ˂ 0.05

Answer 24

reject the null hypothesis

Question 25

P- value ˃ 0.05

Answer 25

not reject the null hypothesis.

Question 26

P-value ˃ Alpha,

Answer 26

the difference between groups not statistically significant.

Question 27

P-value ˂ Alpha

Answer 27

Statistically significantly different between groups. Less than 5 percent prob that null hypothesis is true.

Question 28

Whether a p-value is low or high?

Answer 28

Determined by Level of significance or alpha.

Question 29

P value= 0.001 (under 0.05) interpretation=

Answer 29

there is a probability of 0.001 that you mistakenly reject the null hypothesis.

Question 30

Low p-value:

Answer 30

reject the null hypothesis,

Question 31

high p-value:

Answer 31

fail to reject null.

Question 32

The t-test just

Answer 32

not consider the mean but also consider the standard deviation in analysis the difference between two sets of data.

Question 33

One-tailed test:

Answer 33

1- detect the effect in one direction 2- will test either the mean is greater than x or the mean less than x but NOT both of them. Ex, in close-ended questions (Yes/ No). Are boys significantly taller than girls or are girls significantly taller than boys?

Question 34

Two-tailed test:

Answer 34

test both when mean is significantly greater than x and if the mean significantly greater lower than x. ex. Open-ended questions: is there a significant difference between the height of boys and the height of girls? So girls or boys could be taller!

Question 35

Every spread of the data until two standard deviations

Answer 35

consider normal.

Question 36

Anything in the 95 percent of data under the normal distribution

Answer 36

considers as normal.

Question 37

the bigger sample

Answer 37

the close we get the actual numbers.

Question 38

After 30 degrees of freedom,

Answer 38

the t-statistics table becomes relatively the same as z-statistics (normal distribution), so for more than 50 observations, we use z table instead of the t table.

Question 39

The purpose of the t-student test:

Answer 39

is there a significant difference between two sets of data?

Question 40

In t statistic test:

Answer 40

The t=b1/Sb1

Question 41

One tail test

Answer 41

Hypothesis testing is run to determine whether a claim is true or not, given a population parameter. A test that is conducted to show whether the mean of the sample is significantly greater than and significantly less than the mean of a population is considered a two-tailed test.

Question 42

Two tail test

Answer 42

A Two-Tailed Hypothesis is used in statistical testing to determine the relationship between a sample and a distribution. In statistics, you compare a sample (Example: one class of high school seniors SAT scores) to a larger set of numbers, or a distribution (the SAT scores for all US high school seniors).