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82 Cards in this Set
- Front
- Back
The t distribution always has n degrees of freedom |
False |
|
When the margin of error is added to and subtracted from the sample mean, an interval formed that will contain a probability of |
True |
|
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 |
True |
|
The exact spread of the distribution depends on the |
Number of degree of freedom |
|
The exact spread of the distribution depends on the |
Number of degree of freedom |
|
The t distribution approaches the distribution as the sample size |
Z, increases |
|
The exact spread of the distribution depends on the |
Number of degree of freedom |
|
The t distribution approaches the distribution as the sample size |
Z, increases |
|
The width of a confidence interval will be |
narrower for 90 percent confidence than for percent confidence. |
|
The exact spread of the distribution depends on the |
Number of degree of freedom |
|
The t distribution approaches the distribution as the sample size |
Z, increases |
|
The width of a confidence interval will be |
narrower for 90 percent confidence than for percent confidence. |
|
As standard deviation increases , sample size to achieve a specified level of confidence |
Increases |
|
The exact spread of the distribution depends on the |
Number of degree of freedom |
|
The t distribution approaches the distribution as the sample size |
Z, increases |
|
The width of a confidence interval will be |
narrower for 90 percent confidence than for percent confidence. |
|
As standard deviation increases , sample size to achieve a specified level of confidence |
Increases |
|
When determining the sample size If the value found not an integer you shouldchoose the highest Integer value |
Always |
|
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 |
T distribution |
|
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 |
T distribution |
|
When the sample size and the proportion prematn the same, a percent confidence the 99 for |
narrow than |
|
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 |
True |
|
A Type error is rejecting a true null hypothesis. |
True |
|
The larger the pvaluethe more we doubt the null hypothesis |
False |
|
A Type error falling to reject a false null hypothesis. |
True |
|
A Type error falling to reject a false null hypothesis. |
True |
|
the for a population proportion or meanIf level of significance is less than the p value, the null hypothesis is rejected |
False |
|
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 |
Z |
|
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 |
Z |
|
For a fixed sample size, the lower we athe higher is the |
Type ll error |
|
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 |
Z |
|
For a fixed sample size, the lower we athe higher is the |
Type ll error |
|
As Type errorof statistical tost increases the power of the |
Decreases |
|
Assuming that the null hypothesis the the of a of the stand that as extreme as the valise computed from the sample |
P- Value |
|
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. |
n1+n2 -2 |
|
Which of the following samples are paired? Select all that apply |
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 |
|
To test if the two independent population have equal variances, we use |
F test |
|
What was the trick that I shared with you in the step of calculating the test statistics F^ + |
always assign subscription 1 to the sample with larger sample variance |
|
The F distribution is |
Skewed to the right |
|
F-distribution has two parameters: numerator degrees of freedom and denominator degrees of freedom. |
True |
|
What is the TOTAL sample size of the example given in this video? |
800 |
|
When the sample size is large, what distribution can we assume for the sample proportion? |
Normal distribution |
|
an inependent samples expertment an experiment in which there is no relationship between the measurements in the different samples |
True |
|
an inependent samples expertment an experiment in which there is no relationship between the measurements in the different samples |
True |
|
in forming a confidence interval for mu 1 - mu 2 only two assumptions are required independent samples and sample sizes of at least 30 |
False |
|
an inependent samples expertment an experiment in which there is no relationship between the measurements in the different samples |
True |
|
in forming a confidence interval for mu 1 - mu 2 only two assumptions are required independent samples and sample sizes of at least 30 |
False |
|
an experiment involving matched pairsa sample of 12 pairs of observations is collectedThe degrees of freedom for the statistic 10 |
False |
|
an inependent samples expertment an experiment in which there is no relationship between the measurements in the different samples |
True |
|
in forming a confidence interval for mu 1 - mu 2 only two assumptions are required independent samples and sample sizes of at least 30 |
False |
|
an experiment involving matched pairsa sample of 12 pairs of observations is collectedThe degrees of freedom for the statistic 10 |
False |
|
When comparing two Independent population means, n 1 =13 and n 2 =10, degrees of freedom for the 22 |
False |
|
an inependent samples expertment an experiment in which there is no relationship between the measurements in the different samples |
True |
|
in forming a confidence interval for mu 1 - mu 2 only two assumptions are required independent samples and sample sizes of at least 30 |
False |
|
an experiment involving matched pairsa sample of 12 pairs of observations is collectedThe degrees of freedom for the statistic 10 |
False |
|
When comparing two Independent population means, n 1 =13 and n 2 =10, degrees of freedom for the 22 |
False |
|
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 |
False |
|
In testing for the equality of means from two wdependent populations. the hypothesis of equal populamon means is rejected |
Always |
|
In testing for the equality of means from two wdependent populations. the hypothesis of equal populamon means is rejected |
Always |
|
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 |
PIternet - p s -P store <=.18 . |
|
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 |
matched pairs from two dependent populations |
|
In testing the difference between the means of two normally distributed populations using Independent random sam |
t statistic |
|
When testing the difference between two population proportions using large independent random samples, the |
Z |
|
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 |
u consumer > u banking |
|
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 |
9 |
|
A simple linear regression model is to study the relationship between |
two continuous random variables |
|
Which of the following is a point estimate of the slope of the simple linear regression? |
b1 |
|
r ^ 2 model 1 and 2 is 0.91 and 0.74, respectively, which model has a better fit? |
Model 1 |
|
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) |
r<0 |
|
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) |
r<0 |
|
What are the assumptions for the error term in the simple linear regression? Check all that apply . |
Zero mean Normality Constant variance Independence |
|
In the simple linear regression , what is the degrees of freedom of SSE? Let's denote n fo the sample size . |
n-2 |
|
In the simple linear regression , what is the degrees of freedom of SSE? Let's denote n fo the sample size . |
t test |
|
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? |
n-2 |
|
The dependent variable is the variable that is being described or predicted |
True |
|
the difference between an Individual value of the dependent variable and the corresponding mean va |
False |
|
A simple linear regression model is an equation that describes the stralght-line relationship between a dependent variable and an independent variable |
True |
|
The residual is the difference between the observed value of the dependent varlable and the predicted value of the dependent variable |
True |
|
In a simple linear regression analysis, the correlation coefficient () and the slope (b)\ \ have the same sign |
Always |
|
All of the following are assumptions of the error terms the simple linear regression model except |
error tems are dependent on each other |
|
Themeasures the strength of the linear relationship between the dependent variable and the independent variable |
Correlation coefficient |
|
The least squares regression line minimizes the sum of the |
squared differences between actual and predicted Y values |