Select all choices that are appropriate for an independent two-sample situation.
A. Any husband and any wife.
B. Any husband and their wife.
C. Any student tested before a semester and the same student tested after a semester.
D. Any student tested before a semester and any student tested after a semester.
A & D
Select all choices that are appropriate for an independent two-sample situation.
A. A random sample of individuals divided into two groups.
B. A random sample of pairs of individuals
C. A random sample from one population and a random sample from another population..
D. A random sample from one population and a matched sample from another population.
A & C
Using the method to Determine Sample Dependency, select the choice that is appropriate for an independent two-sample situation.
A.
For an independent two-sample situation, select the choice that expresses the statistical logic used to work with two samples of independent information.
A. Treat the information as a random selection of pairs.
B. Statistically analyze the individual data values.
C. Must treat the information in each sample separately.
D. Statistically analyze the differences between pairs of data values.
C & D
For an independent two-sample situation, does it matter how the difference is calculated?
D.
For an independent two-sample situation, select the two most appropriate degrees of freedom?
A. The usual degrees of freedom: (n_d - 1) when the population variances are considered equal
B. Pooled degrees of freedom: when the population variances are considered equal.
C. Satterthwaite's approximate degrees of freedom (given in the problem), when the population variances are considered not equal.
D. Independent degrees of freedom: ((n₁-1) + (n₂-1)) / ((n₁-1)+(n₂-1) when the population variances are considered not equal.
B & C
For an independent two-sample situation, what is the appropriate degrees of freedom with the information below?
Levene's p-value: 0.01
Pooled df: 98
Satterthwaite's df:89.783
D.
Since 0.01< 0.05, you pick Satterthwaite. If Satterthwaite is not available look for welches.
For an independent two-sample situation, what is the appropriate degrees of freedom with the information below?
Levene's p-value :0.10
Pooled df: 14
Satterthwaite's df:13.563
A.
Used pooled because 0.10> 0.05
The results of Levene's test is needed to properly interpret every independent two-sample t-test.
True
False
True
For an independent two-sample situation, what is the value in the null hypothesis?
C.
For the situation shown below, match each statistic with its appropriate value.
A weight-lifting coach claims that weight-lifters can increase their strength by taking a certain supplement. To test his theory, the coach randomly selects 9 athletes and tests their strength on a bench press. He then randomly selects 9 more athletes, gives them the supplement for 30 days, and tests their strength. The statistical results are shown below. (H(0): (Before - After) = 0, and the data values are distributed normally.) Test the coach's claim that the supplement works using a significance level of 0.10.
n
x̄
s
Before:
9
222
31.6
After:
9
227
35.1
The conclusion:
9
-4.78
6.24
A. The test statistic.
B. The critical value.
C. The p-value.
D. The conclusion.
Critical Value: Using 0.10 and df= 8 we get the area
= -1.397
Test Statistic: Use equation: (x̄1 - x̄2) / (√s²/n1) + (√s²/n2)
= -0.317
p-value: Using -0.317 and df= 8, we see that the p-value is so far left that it is greater than 0.25
Conclusion: Because p>α, we do not reject
For the situation shown below, match each statistic with its appropriate value.
A study was conducted to find out if the salaries of elementary school teachers were equal to high school teachers. The researcher randomly selected 15 high school teachers and randomly selected 15 elementary school teachers. The statistical results are shown below. (Salaries are in $0,000, H(0): (High School - Elementary) = 0, and the data values are distributed normally.) Test the researcher's claim that the salaries are equal using a significance level of 0.05.
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A. The test statistic.
B. The critical value.
C. The p-value.
D. The conclusion.
Critical Value: Using 0.05/2= 0.025 and df= 14 we get the area
= +/- 2.145
Test Statistic: Use equation: (x̄1 - x̄2) / (√s²/n1) + (√s²/n2)
= +3.50
p-value: 0.005
Conclusion: Reject H(0)
For the situation shown below, match each statistic with its appropriate value.
A sugar maple grower long suspected that his trees produced a different amount of sugar maple syrup at night time, than during the day time. Having just retired, he decided to find out. He randomly chose 27 sugar maple trees and measured their syrup output at night. Then, he randomly chose 27 more sugar maple trees and measured their syrup output during the day. The statistical results are shown below. (Syrup production is in lbs, H(0): (Day time – Night time = 0, and the data values are distributed normally.) Test the grower's claim that the syrup production is different using a significance level of 0.05.
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A. The test statistic.
B. The critical value.
C. The p-value.
D. The conclusion.
Critical Value: Using 0.05 and df= 26 we get the area= +/- 2.056
Test Statistic
: Use equation: (x̄1 - x̄2) / (√s²/n1) + (√s²/n2)
= -3.358
p-value: 0.002
Conclusion: Reject H(0)
For the situation shown below, match each statistic with its appropriate value.
A forester was responsible for growing pine trees as fast as possible to supply a local paper mill. He wondered if it made a difference whether the tree was planted just to the south, or just to the north, of another pine tree. To be able to make a decision based on evidence, he sought out 18 pine trees planted just to the north and measured their height. He then found 18 pine trees planted just to the south and measured their height. The statistical results are shown below. (Height is in feet, the difference is calculated as (North - South), and the data values are distributed normally.) Test the forester's claim that the trees are not equal in height at a significance level of 0.10.
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A. The test statistic.
B. The critical value.
C. The p-value.
D. The conclusion.
Critical Value: Using 0.10 and df= 17 we get the area
= +/- 1.740
Test Statistic: Use equation: (x̄1 - x̄2) / (√s²/n1) + (√s²/n2)
= -3.831
p-value: 0.0005
Conclusion: Reject H(0)
For the situation shown below, match each statistic with its appropriate value.
Early in the HIV epidemic, health care staff had poor knowledge of the HIV transmission risks and were reluctant to care for HIV patients. To remediate this reluctance, a short training program was developed to improve the knowledge of health care staff. The knowledge of some staff members were measured before the training program, and the knowledge of other staff members were measured after the training program. The statistical results are shown below. (Knowledge is in units, the difference is calculated as (After - Before), and the data values are distributed normally.) Test that this training program was effective at increasing the staff's measure of knowledge about HIV transmission risk using a significance level of 0.05.
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A. The test statistic.
B. The critical value.
C. The p-value.
D. The conclusion.
Critical Value: Using 0.05...
= +1.761
Test Statistic
: Use equation: (x̄1 - x̄2) / (√s²/n1) + (√s²/n2)
= +2.398
p-value: 0.02
Conclusion: Reject H(0)
For the situation below, what is the appropriate interpretation of the statistical results?
A sociological researcher studied children and noticed that male children seemed to weigh more than female children of the same age. She designed and conducted an experiment and used an independent two-sample t-test to get the statistical results below.
For the situation below, what is the appropriate interpretation of the statistical results?
A sociological researcher studied children and noticed that male children seemed to weigh more than female children of the same age. She designed and conducted an experiment and used an independent two-sample t-test to get the statistical results below.
Alpha: 0.02
Critical Value: +2.398
Test Statistic: +1.833
p-Value: 0.05
A. Both genders of children had the same weight.
B. The two genders of children had different weights.
C. The male gender weighed more than the female gender.
D. Both genders of children were weighed.
A.
For the situation below, what is the appropriate interpretation of the statistical results?
A forester was responsible for growing pine trees as fast as possible to supply a local paper mill. He wondered if it made a difference whether the tree was planted just to the south, or just to the north, of another\n pine tree. After his experiment, he ran an independent two-sample t-test and got the statistical results below.
Alpha: 0.10
Critical Value: +1.315
Test Statistic: +3.067
p-Value: 0.0025
A. The trees planted just to the south grew the same as the trees planted to just to the north.
B. The trees planted just to the south grew 3.067/1.315 = 2.33 times faster than the trees planted to just to the north.
C. The difference in growth rate as 0.0025, which means both trees grew the same amount.
D. The trees planted just to the south did grow faster than the trees planted to just to the north.
D.
For the situation below, what is the appropriate interpretation of the statistical results?
Early in the HIV epidemic, health care staff had poor knowledge of the HIV transmission risks and were reluctant to care for HIV patients. To remediate this reluctance, a short training program was developed to improve the knowledge of health care staff. A study the program was done and the data analyzed with an independent two-sample t-test. The statistical results are shown below.
Alpha: 0.05
Critical Value: +1.684
Test Statistic: +2.021
p-Value: 0.025
when the population variances are considered equal.