QUESTION 2 A teacher is experimenting with a new computer-based instruction and
ID: 3307154 • Letter: Q
Question
QUESTION 2
A teacher is experimenting with a new computer-based instruction and conducts a study to test its effectiveness. In which situation could the teacher use a hypothesis test for matched pairs?
A. The teacher gives each student in the class a pretest. Then she teaches a lesson using a computer program. Afterwards, she gives each student a post-test. The teacher wants to see if the difference in scores will show an improvement.
B. The teacher randomly divides the class into two groups. One of the groups receives computer-based instruction. The other group receives traditional instruction without computers. After instruction, each student takes a test and the teacher wants to compare the performance of the two groups.
C. The teacher uses a combination of traditional methods and computer-based instruction. She asks students which they liked better. She wants to determine if the majority prefer the computer-based instruction.
QUESTION 3
Research suggests that identical twins have many similarities, such as body weights, even as adults. A sample of ten sets of identical twins were weighed and had their weights recorded in kilograms. The researcher wishes to test whether there is a statistically significant difference in adult weight between first-born and second-born identical twins. Given the design of the study and the question of interest, which of the following 4 computer outputs is relevant to use?
Output A
Output B
Output C
Output D
Output A
Output B
Output C
Output D
QUESTION 4
Some research suggests that first born children may have higher IQ scores than their later born siblings. Do first-born identical twins have higher IQ scores than their second-born sibling? Data from a 1998 study by Tramo, Loftus, Stukel, Weaver, and Gazzaniga were analyzed to determine whether first-born identical twins have higher IQ scores than their second-born siblings. Ten pairs of adult identical twins were assessed and their Full Scale IQ scores were calculated.
Let 1 and 2 represent the mean Full Scale IQ score for all first-born identical twins and second-born identical twins, respectively, and let d be the mean of the differences in IQ score of all identical twins (IQ score of first-born twin - IQ score of second-born twin). Which are the appropriate null and alternative hypotheses?
A. H0: d = 0, Ha: d > 0
B. H0: d = 0, Ha: d < 0
C. H0: d > 0, Ha: d = 0
D. H0: 1= 2, Ha: 1 > 2
E. Both (A) and (D) are correct.
QUESTION 5
Research suggests that the pressure of being timed may interfere with performance on tests that involve mathematical problems. A fictional study was conducted with 30 6th graders. First, the 6th graders were given a math test that contained 50 problems and were told that they had only one hour to complete it (Timed Condition). The same 6th graders were later given a math test that contained 50 problems and were told that they could have as much time, as needed, to complete the test (Unlimited Time Condition). The total number of correct answers for each 6th grader was then calculated for each condition. Then, for each student, the difference between the two scores (Timed-Untimed) was calculated. The researchers hypothesized that the 6th graders would get fewer correct answers, when they took the test with a time limit, as compared to when they had unlimited time. [Tramo MJ, Loftus WC, Green RL, Stukel TA, Weaver JB, Gazzaniga MS. Brain Size, Head Size, and IQ in Monozygotic Twins. Neurology 1998; 50:1246-1252.]
The researchers analyzed the data and obtained the following output.
From the ouput we learn that:
A. The data provide sufficient evidence to reject H0 . Thus, the researchers conclude that 6th grade students get, on average, fewer correct answers and, thus, lower scores on math tests when taking them under timed conditions as compared to untimed conditions.
B. The data provide sufficient evidence to reject H0. Thus, based on the data the researchers cannot conclude that mean number of correct answers on the math test for the Timed Condition is lower compared to the Untimed Condition.
C. The data do not provide sufficient evidence to reject H0. Thus, the researchers conclude that 6th grade students get, on average, fewer correct answers and, thus, lower scores, on math tests, when taking them under timed conditions as compared to untimed conditions.
D. The data do not provide sufficient evidence to reject H0. Thus, based on the data the researchers cannot conclude that mean number of correct answers on the math test for the Timed Condition is lower compared to the Untimed Condition.
QUESTION 6
For which of the following would it be most appropriate to use an ANOVA to analyze the data?
A. A researcher is interested in determining the most effective format for advertising. He randomly assigns 60 people to one of three groups: (1) television commercial, (2) radio commercial, or (3) magazine advertisement. Group members review the commercial and then report whether or not they would buy the product.
B. In order to determine the effectiveness of different diet plans, 90 people are randomly assigned to one of three groups: (1) low calorie diet, (2) low-fat diet, or (3) low-carb diet. At the end of 60 days, the number of pounds lost was recorded for each of the participants.
C. Both A and B.
D. Neither A nor B.
QUESTION 7
To determine whether there is a relationship between the type of school attended and verbal reasoning scores for Irish students, three samples with 25 students, in each group, were randomly selected from data used by Raferty and Hout (1985). One group of students attended secondary school, the second group of students attended vocational school, and the third group consisted of students who attended only primary school. [Raftery, A.E. and Hout, M. (1985). Does Irish education approach the meritocratic ideal? A logistic analysis. Economic and Social Review, 16, 115-140.]
If we let µ1, µ2, and µ3 be the mean verbal reasoning scores for students who attended secondary school, vocational school, and primary school only, respectively, the appropriate hypotheses in this case are:
A. H0: 1 = 2 = 3, Ha: 1, 2, 3, are not all equal
B. H0: 1, 2, 3, are not all equal,
Ha: 1 = 2 = 3
C. H0: 1 = 2 = 3,
Ha: 1 2 3
D. H0: 1 2 3,
Ha: 1 = 2 = 3
E. None of the above are correct.
QUESTION 8
To determine whether there is a relationship between the type of school attended and verbal reasoning scores for Irish students, three samples with 25 students, in each group, were randomly selected from data used by Raferty and Hout (1985). One group of students attended secondary school, the second group of students attended vocational school, and the third group consisted of students who attended only primary school. [Raftery, A.E. and Hout, M. (1985). Does Irish education approach the meritocratic ideal? A logistic analysis. Economic and Social Review, 16, 115-140.]
Here are the three sample standard deviations for the verbal reasoning scores for the three groups (secondary school, vocational school, and primary school only):
Based on this information, do the data meet the condition of equal population standard deviations for the use of the ANOVA?
A. Yes, because 14.18 - 11.71 < 2.
B. Yes, because 14.18/11.71 < 2.
C. No, because the standard deviations are not equal.
D. Unable to determine from the information provided.
QUESTION 9
To determine whether there is a relationship between the type of school attended and verbal reasoning scores for Irish students, three samples with 25 students, in each group, were randomly selected from data used by Raferty and Hout (1985). One group of students attended secondary school, the second group of students attended vocational school, and the third group consisted of students who attended only primary school. [Raftery, A.E. and Hout, M. (1985). Does Irish education approach the meritocratic ideal? A logistic analysis. Economic and Social Review, 16, 115-140.]
The analysis was run on the data and the following output was obtained:
Based on this information, we :
A. Fail to reject the H0 and conclude that the data provide strong evidence that the three mean verbal reasoning scores (representing the three types of schools attended) are not all equal.
B. Fail to reject the H0 and conclude that the data do not provide sufficient evidence that there is a relationship between the type of school attended and verbal reasoning scores for Irish students.
C. Reject the H0 and conclude that the data provide strong evidence that there is a relationship between the type of school attended and verbal reasoning scores for Irish students.
D. Reject the H0 and conclude that the data provide strong evidence that verbal reasoning scores are related to type of school in the following way: the mean verbal reasoning score for Irish students who attended secondary school is higher than the mean verbal reasoning score for Irish students who attended vocational school, which in turn is higher than that of Irish students who attended only primary school.
QUESTION 10
A sleep researcher conducts an experiment where she randomly assigns 60 participants to receive one of three levels of sleep deprivation, sleep deprived for 24 hours (SD24), sleep deprived for 48 hours (SD48), and no sleep deprivation (SD0). After the experimental condition (sleep deprivation), the participants are given an auditory vigilance task and the correct percentages are calculated. The means for the three groups are SD0=76.6, SD24=61.8, SD48=48.6. The ANOVA F test had a p-value=.003. What is your statistical conclusion based on the ANOVA hypotheses?
The group with the most sleep deprivation had a lower mean than the other two groups.
The means for the three conditions were not all equal
The mean for the SD0 group was significantly greater than the mean for the SD24 group which was significantly greater than the mean for the SD48 group
The mean for the non-sleep deprived group performed significantly better than the other two groups.
A. The teacher gives each student in the class a pretest. Then she teaches a lesson using a computer program. Afterwards, she gives each student a post-test. The teacher wants to see if the difference in scores will show an improvement.
B. The teacher randomly divides the class into two groups. One of the groups receives computer-based instruction. The other group receives traditional instruction without computers. After instruction, each student takes a test and the teacher wants to compare the performance of the two groups.
C. The teacher uses a combination of traditional methods and computer-based instruction. She asks students which they liked better. She wants to determine if the majority prefer the computer-based instruction.
Explanation / Answer
Q 2) A teacher is experimenting with a new computer-based instruction and conducts a study to test its effectiveness. In which situation could the teacher use a hypothesis test for matched pairs?
Answer: A. The teacher gives each student in the class a pretest. Then she teaches a lesson using a computer program. Afterwards, she gives each student a post-test. The teacher wants to see if the difference in scores will show an improvement.
Q 3) Outputs are not visible
Q 4) A. H0: d = 0, Ha: d > 0
Q 5) Outputs are not visible
Q 6)For which of the following would it be most appropriate to use an ANOVA to analyze the data?
Answer: C. Both A and B.
Q7 Answer: A. H0: 1 = 2 = 3, Ha: 1, 2, 3, are not all equal
Q 8 Statement not visible
Q 9 Output not visible
Q 10 Answer: The means for the three conditions were not all equal