Biostatistics > LQ2 > Flashcards
LQ2 Flashcards
Hypothesis test is a formal procedure to determine probability that is given hypothesis is true
T/F
True
Null hypothesis is defined as the hypothesis of no difference, no relationship, status quo. This is also the hypothesis that is usually formulated for the purpose of being rejected.
True/False
True
A non-directional hypothesis states whether the value is less than or greater than the other value or hypothesized value
T/F
False
Type II error is committed when the null hypothesis is rejected when it is true
False
The probabilities of Type I and Type II error is denoted by alpha and beta, respectively, a and B are inversely related - decreasing a, increases B
T/F
True
P-value is the actual proabibility of rejecting a null derived from the sample
True/False
True
ANOVA is applicable in comparing the means of two independent groups
T/F
False
T-test for dependent samples is applicable in comparing the means of paired or related samples
T/F
True
in the decision rule, the null hypothesis is rejected when the p-value is less than a
T/F
True
The alternative hypothesis for ANOVA is that all means are equal
T/F
False
Which of the following test is applciable in testing the value of sample mean against the hypothesized mean?
one-sample t-test
Which of the following tests is applicable in testing the differences in the mean of more than 2 independent groups
ANOVA
In testing the meansa of paired or related samples, which of the following is appropriate?
T-test for dependent samples
A psychologist claims that the mean IQ of a sample of 50 children is significantly above the normal IQ of 100. Which of the following is the alternative hypothesis
μ < 100
μ > 100
μ1 < μ2
μ1 > μ2
μ > 100
Results of a study show that female students spend less time studying than male students do.
Let μ1 = mean time spent by female in studying and μ2 = mean time spent by male studying.
Which of the following is the alternative hypothesis?
μ <100
μ > 100
μ1 < μ2
μ1 > μ2
μ1 < μ2
The grade of COS students in Elementary Statistics is the same with the grades of CBA students. Which of the following is the alternative hypothesis?
μ1 = μ2
μ1 /= μ2
μ1 < μ2
μ1 > μ2
μ1 /= μ2
The ideal weight of an aspiring beauty queen is 100 lb. A study showed that the average weight of a group of beauty queens is 108 lbs. Is this group significantly overweight? Which of the following is the alternative hypothesis
μ < 100
μ > 100
μ > 108
μ < 108
μ > 100
Which of the following is equivalent to the statement
“The actual amount is different from P500”?
μ < 500
μ > 500
μ = 500
μ =/ 500
μ =/500
In a company, it was found that the average cost of lunch of 42 employees was 88.07. If the mean cost of lunch of all employees is 100 with a standard deviation of 15, is the average cost of lunch of the employees significantly differs from 100? Use 0.05 level of significance
what is the null hypothesis
μ < 100
μ = 100
μ = 88.07
μ < 88.07
μ = 100
In a company, it was found that the average cost of lunch of 42 employees was 88.07. If the mean cost of lunch of all employees is 100 with a standard deviation of 15, is the average cost of lunch of the employees significantly differs from 100? Use 0.05 level of significance
which of the following is the appropriate test?
one sample t-test
In a company, it was found that the average cost of lunch of 42 employees was 88.07. If the mean cost of lunch of all employees is 100 with a standard deviation of 15, is the average cost of lunch of the employees significantly differs from 100? Use 0.05 level of significance
what is the appropriate alternative hypothesis?
μ < 100
μ =/ 100
μ =/ 88.07
μ < 88.07
μ =/ 100
In a company, it was found that the average cost of lunch of 42 employees was 88.07. If the mean cost of lunch of all employees is 100 with a standard deviation of 15, is the average cost of lunch of the employees significantly differs from 100? Use 0.05 level of significance
If the p-value is 0.023, then what is the decision
Reject Ho
In a company, it was found that the average cost of lunch of 42 employees was 88.07. If the mean cost of lunch of all employees is 100 with a standard deviation of 15, is the average cost of lunch of the employees significantly differs from 100? Use 0.05 level of significance
Which of the following is the hypothesized mean?
100
In a company, it was found that the average cost of lunch of 42 employees was 88.07. If the mean cost of lunch of all employees is 100 with a standard deviation of 15, is the average cost of lunch of the employees significantly differs from 100? Use 0.05 level of significance
which of the following is the sample mean
88.07
In a company, it was found that the average cost of lunch of 42 employees was 88.07. If the mean cost of lunch of all employees is 100 with a standard deviation of 15, is the average cost of lunch of the employees significantly differs from 100? Use 0.05 level of significance
Based on your decision, which of the following is the correct conclusion
There is not enough evidence to prove that the average cost of lunch of the employees significantly differs from 100
There is enough evidence to prove that the average cost of lunch of employees significantly differs from 100
The average cost of lunch of the employees is equal to 88.07
No conclusion can be made.
There is enough evidence to prove that the average cost of lunch of employees significantly differs from 100
A college professor claims that the average performance of her class in Biology is 83. To test this claim, 25 students were randomly selected from the class and the performance was collected.
level of significance - 5%
mean = 82.920
std deviation = 4.600
one sample t-test result
p = 0.931
which of the following is the correct null hypothesis?
The average performance of students in Biology is not equal to 83.
The average performance of students in Biology is equal to 83.
The average performance of students in Biology is less than 85.
The average performance of students in Biology is greater than 85.
The average performance of students in Biology is equal to 83.
A college professor claims that the average performance of her class in Biology is 83. To test this claim, 25 students were randomly selected from the class and the performance was collected.
level of significance - 5%
mean = 82.920
std deviation = 4.600
one sample t-test result
p = 0.931
Which of the following is the alternative hypothesis?
The average performance of students in Biology is not equal to 83.
The average performance of students in Biology is equal to 83.
The average performance of students in Biology is less than 85.
The average performance of students in Biology is greater than 85.
The average performance of students in Biology is not equal to 83.
A college professor claims that the average performance of her class in Biology is 83. To test this claim, 25 students were randomly selected from the class and the performance was collected.
level of significance - 5%
mean = 82.920
std deviation = 4.600
one sample t-test result
p = 0.931
which of the following is the appropriate test statistic?
one sample t-test
A college professor claims that the average performance of her class in Biology is 83. To test this claim, 25 students were randomly selected from the class and the performance was collected.
level of significance - 5%
mean = 82.920
std deviation = 4.600
one sample t-test result
p = 0.931
Based on the result, which of the following is the correct decision?
A. REJECT the alternative hypothesis
B. Fail to reject the alternative hypothesis
C. Fail to reject the null hypothesis
D. Reject the null hypothesis
C. Fail to reject the null hypothesis
A college professor claims that the average performance of her class in Biology is 83. To test this claim, 25 students were randomly selected from the class and the performance was collected.
level of significance - 5%
mean = 82.920
std deviation = 4.600
one sample t-test result
p = 0.931
Based on your decision, which of the following is not the correct implication?
A. the professor claim is not true
B. there is not enough evidence to prove the professor’s claim
C. There is enough evidence to prove the professor’s claim
D. No conclusion can be made
C. There is enough evidence to prove the proffesor’s claim
According to the article “Pratice and Fatigue Effects on Programming of a Coincident Timing Response” published in the Journal of Human Movement Studies in 1997, practice under fatigued conditions distorts mechanisms which govern performance. An experiment was conducted using 15 college males who were trianed to make a continuous horizontal right-to-left arm movement from a micro-switch to a barrier, knocking over the barrier coincident with the arrival of a clock sweep hand to the 6 o’clock.
The absolute value of the difference between the time, in milliseconds, that it took to knock over the barrier and the time for the sweep hand to reach the 6’0 position (500 msec.) was recorded.
Each participant performed the task five times under prefatigue and post fatigue conditions, and the sums of absolute differences for the five performances were recorded.
An increase in the mean absolute time differences when the task is performed under post fatigue conditions would support the claim that practice under fatigued condition distorts mechanism that govern performance. Assuming the populations to be normally distributed.
JASP output
Paired Samples T-Test
p = 0.093
Descriptives
Pre 92.733
Post 108.933
Which of the following is the appropriate alternative hypothesis
μpre = μpost
μ pre /= upost
μpre < μpost
μpre > μpost
μpre < μpost
According to the article “Pratice and Fatigue Effects on Programming of a Coincident Timing Response” published in the Journal of Human Movement Studies in 1997, practice under fatigued conditions distorts mechanisms which govern performance. An experiment was conducted using 15 college males who were trianed to make a continuous horizontal right-to-left arm movement from a micro-switch to a barrier, knocking over the barrier coincident with the arrival of a clock sweep hand to the 6 o’clock.
The absolute value of the difference between the time, in milliseconds, that it took to knock over the barrier and the time for the sweep hand to reach the 6’0 position (500 msec.) was recorded.
Each participant performed the task five times under prefatigue and post fatigue conditions, and the sums of absolute differences for the five performances were recorded.
An increase in the mean absolute time differences when the task is performed under post fatigue conditions would support the claim that practice under fatigued condition distorts mechanism that govern performance. Assuming the populations to be normally distributed.
JASP output
Paired Samples T-Test
p = 0.093
Descriptives
Pre 92.733
Post 108.933
what test statistic is used
t-test for dependent samples
According to the article “Pratice and Fatigue Effects on Programming of a Coincident Timing Response” published in the Journal of Human Movement Studies in 1997, practice under fatigued conditions distorts mechanisms which govern performance. An experiment was conducted using 15 college males who were trianed to make a continuous horizontal right-to-left arm movement from a micro-switch to a barrier, knocking over the barrier coincident with the arrival of a clock sweep hand to the 6 o’clock.
The absolute value of the difference between the time, in milliseconds, that it took to knock over the barrier and the time for the sweep hand to reach the 6’0 position (500 msec.) was recorded.
Each participant performed the task five times under prefatigue and post fatigue conditions, and the sums of absolute differences for the five performances were recorded.
An increase in the mean absolute time differences when the task is performed under post fatigue conditions would support the claim that practice under fatigued condition distorts mechanism that govern performance. Assuming the populations to be normally distributed.
JASP output
Paired Samples T-Test
p = 0.093
Descriptives
Pre 92.733
Post 108.933
what is the decision
Failed to reject the null hypothesis.
According to the article “Pratice and Fatigue Effects on Programming of a Coincident Timing Response” published in the Journal of Human Movement Studies in 1997, practice under fatigued conditions distorts mechanisms which govern performance. An experiment was conducted using 15 college males who were trianed to make a continuous horizontal right-to-left arm movement from a micro-switch to a barrier, knocking over the barrier coincident with the arrival of a clock sweep hand to the 6 o’clock.
The absolute value of the difference between the time, in milliseconds, that it took to knock over the barrier and the time for the sweep hand to reach the 6’0 position (500 msec.) was recorded.
Each participant performed the task five times under prefatigue and post fatigue conditions, and the sums of absolute differences for the five performances were recorded.
An increase in the mean absolute time differences when the task is performed under post fatigue conditions would support the claim that practice under fatigued condition distorts mechanism that govern performance. Assuming the populations to be normally distributed.
JASP output
Paired Samples T-Test
p = 0.093
Descriptives
Pre 92.733
Post 108.933
which of the following is the correct conclusion to the given problem
A. that practice under fatigued conditions distorts mechanisms that govern performance
b. there is not enough evidence to prove the claim
c. the experiment is not effective
d. no conclusion can be made
b. there is not enough evidence to prove the claim
According to the article “Pratice and Fatigue Effects on Programming of a Coincident Timing Response” published in the Journal of Human Movement Studies in 1997, practice under fatigued conditions distorts mechanisms which govern performance. An experiment was conducted using 15 college males who were trianed to make a continuous horizontal right-to-left arm movement from a micro-switch to a barrier, knocking over the barrier coincident with the arrival of a clock sweep hand to the 6 o’clock.
The absolute value of the difference between the time, in milliseconds, that it took to knock over the barrier and the time for the sweep hand to reach the 6’0 position (500 msec.) was recorded.
Each participant performed the task five times under prefatigue and post fatigue conditions, and the sums of absolute differences for the five performances were recorded.
An increase in the mean absolute time differences when the task is performed under post fatigue conditions would support the claim that practice under fatigued condition distorts mechanism that govern performance. Assuming the populations to be normally distributed.
JASP output
Paired Samples T-Test
p = 0.093
Descriptives
Pre Mean - 92.733
Post Mean - 108.933
which of the following is the test statistic value?
A. -16.20
B. 92.73
C. 108.93
D. -1.39
-1.391
A chemist is stuying the effect of the level of catalyst on the concentration of a component in liquid solution. The data are given below. Is there a difference in the mean level of concentration among the four levels of catalyst?
Check picture for more information
JASP output
ANOVA
Levels p value = 0.002
Which of the following is the correct alternative hypothesis
A. there is no significant difference in the mean level of concentration among the four levels of catalyst
B. There is a significant difference in the mean level of concentration into the four levels of catalyst
C. there is a significant difference in the mean level of catalyst among the four levels of concentration
B. There is a significant difference in the mean level of concentration into the four levels of catalyst
A chemist is stuying the effect of the level of catalyst on the concentration of a component in liquid solution. The data are given below. Is there a difference in the mean level of concentration among the four levels of catalyst?
Check picture for more information
JASP output
ANOVA
Levels p value = 0.002
Based on the result, which of the following is the correct decision
Reject the null hypothesis
Failed to reject the null hypothesis
Reject the null hypothesis
A chemist is stuying the effect of the level of catalyst on the concentration of a component in liquid solution. The data are given below. Is there a difference in the mean level of concentration among the four levels of catalyst?
Check picture for more information
JASP output
ANOVA
Levels p value = 0.002
Based on the result, which of the following is the correct decision
Reject the null hypothesis
Which of the following is the implication of your decision?
A. the level of catalyst has no effect on the concentration of a component in a liquid solution
B. The level of concentration has no effect on the level of catalyst in a component in a liquid solution
C. the level of catalyst has an effect on the concentration of a component in a liquid solution
D. cannot be determined
C. the level of catalyst has an effect on the concentration of a component in a liquid solution
A chemist is stuying the effect of the level of catalyst on the concentration of a component in liquid solution. The data are given below. Is there a difference in the mean level of concentration among the four levels of catalyst?
Check picture for more information
JASP output
ANOVA
Levels p value = 0.002
Level 1 69.840
Level 2 68.950
Level 3. 66.800
Level 4 63.700
Base on the descriptive stat, which of the following levels has obtained the highest mean?
Level 1 (A)
A chemist is stuying the effect of the level of catalyst on the concentration of a component in liquid solution. The data are given below. Is there a difference in the mean level of concentration among the four levels of catalyst?
Check picture for more information
JASP output
ANOVA
Levels p value = 0.002
Post Hoc
1 2 Mean difference - 0.890
1 3 Mean difference - 3.040
1 4 Mean difference 6.140
2 3 Mean difference 2.15
2 4 Mean difference 5.25
3 4 Mean difference 3.1
Based on the result of the post hoc, which level of concentration significantly differed from the others?
Level 4
Researchers want to examine perceived control on health complaints of geriatric patients in a long-term care facility. Thirty patients are randomly selected to participate in the study. Half are given a plant to care for and half are given a plant but the care is conducted by the staff. Number of health complaints were recorded for each patient over the following seven days.
JASP output:
number of complaints t = 3.691
number of complaints p <0.001
Descriptives
Number of complaints
No control mean - 27.067
With control= 15.600
What is the null hypothesis
The mean number of health complaints for patients with control over a plant is equal to the mean number of health complaints for patients without control over a plant.
Researchers want to examine perceived control on health complaints of geriatric patients in a long-term care facility. Thirty patients are randomly selected to participate in the study. Half are given a plant to care for and half are given a plant but the care is conducted by the staff. Number of health complaints were recorded for each patient over the following seven days.
JASP output:
number of complaints t = 3.691
number of complaints p <0.001
Descriptives
Number of complaints
No control mean - 27.067
With control= 15.600
What is the alternative hypothesis
The mean number of health complaints for patients with control over a plant is not equal to the mean number of health complaints for patients without control over a plant.
Researchers want to examine perceived control on health complaints of geriatric patients in a long-term care facility. Thirty patients are randomly selected to participate in the study. Half are given a plant to care for and half are given a plant but the care is conducted by the staff. Number of health complaints were recorded for each patient over the following seven days.
JASP output:
number of complaints t = 3.691
number of complaints p <0.001
Descriptives
Number of complaints
No control mean - 27.067
With control= 15.600
alpha is?
0.05
Researchers want to examine perceived control on health complaints of geriatric patients in a long-term care facility. Thirty patients are randomly selected to participate in the study. Half are given a plant to care for and half are given a plant but the care is conducted by the staff. Number of health complaints were recorded for each patient over the following seven days.
JASP output:
number of complaints t = 3.691
number of complaints p <0.001
Descriptives
Number of complaints
No control mean - 27.067
With control= 15.600
n is ?
30
Researchers want to examine perceived control on health complaints of geriatric patients in a long-term care facility. Thirty patients are randomly selected to participate in the study. Half are given a plant to care for and half are given a plant but the care is conducted by the staff. Number of health complaints were recorded for each patient over the following seven days.
JASP output:
number of complaints t = 3.691
number of complaints p <0.001
Descriptives
Number of complaints
No control mean - 27.067
With control= 15.600
test statistic will be?
T-test for dependent samples
Researchers want to examine perceived control on health complaints of geriatric patients in a long-term care facility. Thirty patients are randomly selected to participate in the study. Half are given a plant to care for and half are given a plant but the care is conducted by the staff. Number of health complaints were recorded for each patient over the following seven days.
JASP output:
number of complaints t = 3.691
number of complaints p <0.001
Descriptives
Number of complaints
No control mean - 27.067
With control= 15.600
what is the decision rule
Reject Ho if p < 0.05
Researchers want to examine perceived control on health complaints of geriatric patients in a long-term care facility. Thirty patients are randomly selected to participate in the study. Half are given a plant to care for and half are given a plant but the care is conducted by the staff. Number of health complaints were recorded for each patient over the following seven days.
JASP output:
number of complaints t = 3.691
number of complaints p <0.001
Descriptives
Number of complaints
No control mean - 27.067
With control= 15.600
what is the decision
since p is <.0001 and is <0.05, the null hypothesis is rejected
Researchers want to examine perceived control on health complaints of geriatric patients in a long-term care facility. Thirty patients are randomly selected to participate in the study. Half are given a plant to care for and half are given a plant but the care is conducted by the staff. Number of health complaints were recorded for each patient over the following seven days.
JASP output:
number of complaints t = 3.691
number of complaints p <0.001
Descriptives
Number of complaints
No control mean - 27.067
With control= 15.600
what is the conclusion
Perceived control has a significant effect on health complaints on geriatric patients in a long-term care facility.
