Exam 1 Review biostats/47
Answered questions
Which of the following variables is/are quantitative? (Mark all that apply)
The number of people in a randomly selected classroom on campus
The 3 most common brands of car found in the US
The telephone number of a randomly selected business in town - - The
number of people in a randomly selected classroom on campus
- Which one of the following is a statistically valid reason for sampling
randomly when choosing subjects for a study?
Correct Response
Sampling randomly tends to reduce sampling bias or risk
Sampling randomly (with a large sample) gives a perfect reflection of the
population
Sampling randomly is easier than sampling nonrandomly
Actually, there is no statistically valid reason for sampling randomly - -
Sampling randomly tends to reduce sampling bias or risk
- A study conducted by researchers from the Department of Education
wanted to know the average debt of college students in the United States. In
order to obtain a sample representative of all students, the researchers
divided college students into the four classes (freshman, sophomore, junior,
and senior) and then took a random sample of students from each class.
Which sampling method did they use?
Stratified random sampling
Systematic random sampling
,Cluster sampling
Simple random sampling - - Stratified random sampling
- Students in an Introductory Statistics class at BYU-Idaho were studying
prices of cold cereal at grocery stores in Rexburg. To get a sample of cold
cereal prices, they went to Albertson's and rolled a die to decide which box
from the left of the top shelf they would start on. They then recorded every
6th cereal after the first, moving from left to right down the shelves,
recording the name, size, and price of each cereal in their sample. Which
sampling method did they use?
Stratified random sampling
Systematic random sampling
Cluster sampling
Simple random sampling - - Systematic random sampling
- Is the study described in the previous question an experiment or an
observational study, and why?
An experiment, because the students had control over which sampling
method they used
An experiment, because the students had control over which cereals would
be selected for the study
An observational study, because the students had no control over the price
of the individual cereals
An observational study, because the students had no control over which
cereals were selected - - An observational study, because the students had
no control over the price of the individual cereals
- Which of the following studies depicts an observational study?
, A parent group examines 25 recently released PG-13 movies and records the
number of sexual innuendos and curse words that occur in each.
A sample of 504 patients in early stages of Alzheimer's disease is divided
into two groups. One group receives an experimental drug and the other a
placebo. The advance of the disease is tracked at one-month intervals over
the next year. - - A parent group examines 25 recently released PG-13
movies and records the number of sexual innuendos and curse words that
occur in each.
- Say that you are a researcher for a large pharmaceutical company that has
produced a new drug that is believed to help reduce the risk of developing
arthritis. You test the drug and compare it to a placebo by randomly
choosing one group of men and women in their 50's to take the drug and one
group of men and women in their 50's to take a placebo. Each participant
takes the drug or placebo for a period of 10 years, after which the effects of
the drug are measured against the effects of the placebo. What (or who) are
the experimental units or subject?
All men and women in their 50's
The men and women who took the drug or placebo
The researchers
The drug and placebo - - The men and women who took the drug or placebo
- Say that you are a researcher for a large pharmaceutical company that has
produced a new drug that is believed to help reduce the risk of developing
arthritis. You test the drug and compare it to a placebo by randomly
choosing one group of men and women in their 50's to take the drug and one
group of men and women in their 50's to take a placebo. Each participant
takes the drug or placebo for a period of 10 years, after which the effects of
the drug are measured against the effects of the placebo. What are the
treatments?
All men and women in their 50's
Answered questions
Which of the following variables is/are quantitative? (Mark all that apply)
The number of people in a randomly selected classroom on campus
The 3 most common brands of car found in the US
The telephone number of a randomly selected business in town - - The
number of people in a randomly selected classroom on campus
- Which one of the following is a statistically valid reason for sampling
randomly when choosing subjects for a study?
Correct Response
Sampling randomly tends to reduce sampling bias or risk
Sampling randomly (with a large sample) gives a perfect reflection of the
population
Sampling randomly is easier than sampling nonrandomly
Actually, there is no statistically valid reason for sampling randomly - -
Sampling randomly tends to reduce sampling bias or risk
- A study conducted by researchers from the Department of Education
wanted to know the average debt of college students in the United States. In
order to obtain a sample representative of all students, the researchers
divided college students into the four classes (freshman, sophomore, junior,
and senior) and then took a random sample of students from each class.
Which sampling method did they use?
Stratified random sampling
Systematic random sampling
,Cluster sampling
Simple random sampling - - Stratified random sampling
- Students in an Introductory Statistics class at BYU-Idaho were studying
prices of cold cereal at grocery stores in Rexburg. To get a sample of cold
cereal prices, they went to Albertson's and rolled a die to decide which box
from the left of the top shelf they would start on. They then recorded every
6th cereal after the first, moving from left to right down the shelves,
recording the name, size, and price of each cereal in their sample. Which
sampling method did they use?
Stratified random sampling
Systematic random sampling
Cluster sampling
Simple random sampling - - Systematic random sampling
- Is the study described in the previous question an experiment or an
observational study, and why?
An experiment, because the students had control over which sampling
method they used
An experiment, because the students had control over which cereals would
be selected for the study
An observational study, because the students had no control over the price
of the individual cereals
An observational study, because the students had no control over which
cereals were selected - - An observational study, because the students had
no control over the price of the individual cereals
- Which of the following studies depicts an observational study?
, A parent group examines 25 recently released PG-13 movies and records the
number of sexual innuendos and curse words that occur in each.
A sample of 504 patients in early stages of Alzheimer's disease is divided
into two groups. One group receives an experimental drug and the other a
placebo. The advance of the disease is tracked at one-month intervals over
the next year. - - A parent group examines 25 recently released PG-13
movies and records the number of sexual innuendos and curse words that
occur in each.
- Say that you are a researcher for a large pharmaceutical company that has
produced a new drug that is believed to help reduce the risk of developing
arthritis. You test the drug and compare it to a placebo by randomly
choosing one group of men and women in their 50's to take the drug and one
group of men and women in their 50's to take a placebo. Each participant
takes the drug or placebo for a period of 10 years, after which the effects of
the drug are measured against the effects of the placebo. What (or who) are
the experimental units or subject?
All men and women in their 50's
The men and women who took the drug or placebo
The researchers
The drug and placebo - - The men and women who took the drug or placebo
- Say that you are a researcher for a large pharmaceutical company that has
produced a new drug that is believed to help reduce the risk of developing
arthritis. You test the drug and compare it to a placebo by randomly
choosing one group of men and women in their 50's to take the drug and one
group of men and women in their 50's to take a placebo. Each participant
takes the drug or placebo for a period of 10 years, after which the effects of
the drug are measured against the effects of the placebo. What are the
treatments?
All men and women in their 50's
