Exam 1 - PBSI 245 questions and
answers graded A+
A researcher studied whether meeting regularly with a weight-loss counselor helps dieters lose
weight. Eighty dieters were available for the study. Half the dieters, assigned at random,
received weight-loss counseling. The other half did not. After six months, the weight lost by
each dieter was measured. On average, those who met regularly with a weight-loss counselor
lost more weight than those who did
not.
*This study is a(n)*
- observational study without SRS
- randomized comparative experiment
- simple random sample
- experiment, but without randomization - correct answer ✔✔- randomized comparative
experiment
A researcher studied whether meeting regularly with a weight-loss counselor helps dieters lose
weight. Eighty dieters were available for the study. Half the dieters, assigned at random,
received weight-loss counseling. The other half did not. After six months, the weight lost by
each dieter was measured. On average, those who met regularly with a weight-loss counselor
lost more weight than those who did
not.
*In order to create groups of subjects that should be similar, on average, in all respects, we
use:*
,- lurking
- confounding
- randomization
-all of the above - correct answer ✔✔- randomization
A researcher studied whether meeting regularly with a weight-loss counselor helps dieters lose
weight. Eighty dieters were available for the study. Half the dieters, assigned at random,
received weight-loss counseling. The other half did not. After six months, the weight lost by
each dieter was measured. On average, those who met regularly with a weight-loss counselor
lost more weight than those who did
not.
*How many groups were in this study? (use an integer)*
_________ - correct answer ✔✔2
XXXXXXXXXXXXXXXXXXXXX
*A nephew visits his Aunt Tess for 5 days. Every morning he weighs himself, and the five
readings are very different. When he gets home and compares the average from his aunt's scale
to the reading on his scale (which he regards as his true weight), he realizes the average is
almost exactly the same. As a measure of his weight on his scale, the reading on his aunt's scale
is.*
- unbiased and reliable
- unbiased and unreliable
xxx biased and reliable
- biased and unreliable
- 95% accurate - correct answer ✔✔could be unbiased and unreliable but idk
XXXXXXXXXXXXXXXXXXXXXXXXXXX
, Does taking large amounts of vitamins protect against cancer? To study this question,
researchers enrolled 29,000 Finnish men, all smokers over the age of 50. Half of the men,
selected at random, took vitamin supplements, and others took a dummy pill that has no active
ingredient. The researchers followed all the men for
eight years. At the end of the study, men in the vitamin group were no less likely to have cancer
than men in the other group. This study cast doubt on the popular idea that taking lots of
vitamins can reduce the risk of cancer.
*The statistical name for this study design is*
- stratified random sample
- multistage sample
xxx sample random sample
- randomized comparative experiment - correct answer ✔✔randomized comparative
experiment
Does taking large amounts of vitamins protect against cancer? To study this question,
researchers enrolled 29,000 Finnish men, all smokers over the age of 50. Half of the men,
selected at random, took vitamin supplements, and others took a dummy pill that has no active
ingredient. The researchers followed all the men for
eight years. At the end of the study, men in the vitamin group were no less likely to have cancer
than men in the other group. This study cast doubt on the popular idea that taking lots of
vitamins can reduce the risk of cancer.
*The method used to form the groups should appear in the outline at the point marked
"Question A." What is this method?*
- divide and conquer
- random assignment
- stratified sampling
answers graded A+
A researcher studied whether meeting regularly with a weight-loss counselor helps dieters lose
weight. Eighty dieters were available for the study. Half the dieters, assigned at random,
received weight-loss counseling. The other half did not. After six months, the weight lost by
each dieter was measured. On average, those who met regularly with a weight-loss counselor
lost more weight than those who did
not.
*This study is a(n)*
- observational study without SRS
- randomized comparative experiment
- simple random sample
- experiment, but without randomization - correct answer ✔✔- randomized comparative
experiment
A researcher studied whether meeting regularly with a weight-loss counselor helps dieters lose
weight. Eighty dieters were available for the study. Half the dieters, assigned at random,
received weight-loss counseling. The other half did not. After six months, the weight lost by
each dieter was measured. On average, those who met regularly with a weight-loss counselor
lost more weight than those who did
not.
*In order to create groups of subjects that should be similar, on average, in all respects, we
use:*
,- lurking
- confounding
- randomization
-all of the above - correct answer ✔✔- randomization
A researcher studied whether meeting regularly with a weight-loss counselor helps dieters lose
weight. Eighty dieters were available for the study. Half the dieters, assigned at random,
received weight-loss counseling. The other half did not. After six months, the weight lost by
each dieter was measured. On average, those who met regularly with a weight-loss counselor
lost more weight than those who did
not.
*How many groups were in this study? (use an integer)*
_________ - correct answer ✔✔2
XXXXXXXXXXXXXXXXXXXXX
*A nephew visits his Aunt Tess for 5 days. Every morning he weighs himself, and the five
readings are very different. When he gets home and compares the average from his aunt's scale
to the reading on his scale (which he regards as his true weight), he realizes the average is
almost exactly the same. As a measure of his weight on his scale, the reading on his aunt's scale
is.*
- unbiased and reliable
- unbiased and unreliable
xxx biased and reliable
- biased and unreliable
- 95% accurate - correct answer ✔✔could be unbiased and unreliable but idk
XXXXXXXXXXXXXXXXXXXXXXXXXXX
, Does taking large amounts of vitamins protect against cancer? To study this question,
researchers enrolled 29,000 Finnish men, all smokers over the age of 50. Half of the men,
selected at random, took vitamin supplements, and others took a dummy pill that has no active
ingredient. The researchers followed all the men for
eight years. At the end of the study, men in the vitamin group were no less likely to have cancer
than men in the other group. This study cast doubt on the popular idea that taking lots of
vitamins can reduce the risk of cancer.
*The statistical name for this study design is*
- stratified random sample
- multistage sample
xxx sample random sample
- randomized comparative experiment - correct answer ✔✔randomized comparative
experiment
Does taking large amounts of vitamins protect against cancer? To study this question,
researchers enrolled 29,000 Finnish men, all smokers over the age of 50. Half of the men,
selected at random, took vitamin supplements, and others took a dummy pill that has no active
ingredient. The researchers followed all the men for
eight years. At the end of the study, men in the vitamin group were no less likely to have cancer
than men in the other group. This study cast doubt on the popular idea that taking lots of
vitamins can reduce the risk of cancer.
*The method used to form the groups should appear in the outline at the point marked
"Question A." What is this method?*
- divide and conquer
- random assignment
- stratified sampling
