Question 1

Identify the variable of interest in the study.
-A clinic gives a drug to a group of ten patients and a placebo to another group of ten patients to find out if the
Drug has an effect on the patients' illness.

Accepted Answer

The variable of interest is the effect of the drug on the patients' illness, as the study aims to determine this outcome.

Question 2

Is the study experimental or observational?
-A stock analyst selects a stock from a group of twenty for investment by choosing the stock with the greatest
Earnings per share reported for the last quarter.

Accepted Answer

The study is observational because the analyst is making a decision based on existing data (earnings per share) without manipulating any variables or conditions.

Question 3

Is the study experimental or observational?
-A quality control specialist compares the output from a machine with a new lubricant to the output of machines
With the old lubricant.

Accepted Answer

The study is experimental because the quality control specialist actively changes a variable (the type of lubricant) to observe its effect on the output, which is a hallmark of experimental studies.

Question 4

Is the study experimental or observational?
-A doctor induces a cardiac stress test to determine the reason for a patient's illness.

Accepted Answer

The study is experimental because the doctor actively intervenes by inducing a cardiac stress test to observe its effects on the patient.

Question 5

Identify the variable of interest in the study.
-A marketing firm does a survey to find out how many people use a product. Of the one hundred people
Contacted, fifteen said they use the product.

Accepted Answer

The variable of interest is the individual responses to the survey question, as the study aims to determine how many people use the product based on these responses.

Question 6

Is the study experimental or observational?
-An Information Technology Manager compares the average time required for 12 megabyte downloads using a
Standard dial-up connection and using a cable modem.

Accepted Answer

In this study, the Information Technology Manager actively manipulates the conditions by comparing download times between two different types of internet connections (standard dial-up and cable modem), which is characteristic of an experimental study.

Question 7

Identify the variable of interest in the study.
-A doctor performs several diagnostic tests to determine the reason for a patient's illness.

Accepted Answer

The variable of interest is the outcome or result of the diagnostic tests, as these are what the doctor analyzes to determine the reason for the patient's illness.

Question 8

Identify the variable of interest in the study.
-Researchers at a university lab found that a genetically modified insect frog a toxin through its skin.

Accepted Answer

The variable of interest is the amount of toxin released through the frog's skin, as the study focuses on the toxin production of genetically modified insect frogs.

Question 9

Identify the variable of interest in the study.
-A T.V. show's executives raised the fee for commercials following a report that the show received a "No. 1"
Rating in a survey of viewers.

Accepted Answer

The answer of Identify the variable of interest in the...

Question 10

Is the study experimental or observational?
-A sample of fish is taken from a lake to measure the effect of pollution from a nearby factory on the fish.

Accepted Answer

This study is observational because the researcher is not manipulating the variable (pollution from the factory). Instead, they are simply observing the effects on the fish.

Question 11

Is the study experimental or observational?
-A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided.

Accepted Answer

This is an observational study because it involves collecting data without influencing the results. The pollster is simply observing and reporting the current preferences of the population.

Question 12

Is the study experimental or observational?
-A marketing firm does a survey to find out how many people use a product. Of the one hundred people
Contacted, fifteen said they use the product.

Accepted Answer

This is an observational study because the marketing firm is simply observing and recording information without attempting to influence or modify the behavior of the participants.

Question 13

Identify the variable of interest in the study.
-A quality control specialist compares the output from a machine with a new lubricant to the output of machines
With the old lubricant.

Accepted Answer

The variable of interest is the difference in output between machines using the new lubricant and those using the old lubricant, as this directly measures the effect of the lubricant change.

Question 14

Identify the variable of interest in the study.
-An analysis of 10 individual studies attempted to determine if there is a conclusive link between "the Pill" and
Ovarian cancer.

Accepted Answer

The variable of interest is whether the subject developed ovarian cancer, as the study aims to determine the link between "the Pill" and ovarian cancer.

Question 15

Identify the variable of interest in the study.
-The highway department paves one section of an Interstate with Type A concrete and an adjoining section with
Type B concrete and observes how long it takes until cracks appear in each.

Accepted Answer

The variable of interest is the length of time it takes for cracks to appear in each type of concrete, as the study aims to compare the durability of Type A and Type B concrete.

Question 16

Is the study experimental or observational?
-The highway department paves one section of an Interstate with Type A concrete and an adjoining section with
Type B concrete and observes how long it takes until cracks appear in each.

Accepted Answer

This is an experimental study because the highway department actively intervenes by using two different types of concrete to compare their durability, rather than merely observing natural occurrences.

Question 17

Is the study experimental or observational?
-A clinic gives a drug to a group of ten patients and a placebo to another group of ten patients to find out if the
Drug has an effect on the patients' illness.

Accepted Answer

This is an experimental study because the clinic is actively intervening by administering a drug to one group and a placebo to another to observe the effects, rather than merely observing natural occurrences.

Question 18

Identify the variable of interest in the study.
-An Information Technology Manager compares the average time required for 12 megabyte downloads using a
Standard dial-up connection and using a cable modem.

Accepted Answer

The variable of interest is the time required for 12 megabyte downloads, specifically comparing the difference in this time between using a standard dial-up connection and a cable modem.

Question 19

Is the study experimental or observational?
-A T.V. show's executives raised the fee for commercials following a report that the show received a "No. 1"
Rating in a survey of viewers.

Accepted Answer

The situation describes an observational study because it involves observing and measuring specific characteristics without attempting to modify the subjects or their environment.

Question 20

Identify the variable of interest in the study.
-A sample of fish is taken from a lake to measure the effect of pollution from a nearby factory on the fish.

Accepted Answer

The variable of interest is the measure of the effect of pollution from the factory on the fish, as the study aims to understand how pollution impacts the fish.

Quiz 1: Speaking of Statistics

Identify the variable of interest in the study. -A clinic gives a drug to a group of ten patients and a placebo to another group of ten patients to find out if the Drug has an effect on the patients' illness.

Is the study experimental or observational? -A stock analyst selects a stock from a group of twenty for investment by choosing the stock with the greatest Earnings per share reported for the last quarter.

Is the study experimental or observational? -A quality control specialist compares the output from a machine with a new lubricant to the output of machines With the old lubricant.

Is the study experimental or observational? -A doctor induces a cardiac stress test to determine the reason for a patient's illness.

Identify the variable of interest in the study. -A marketing firm does a survey to find out how many people use a product. Of the one hundred people Contacted, fifteen said they use the product.

Is the study experimental or observational? -An Information Technology Manager compares the average time required for 12 megabyte downloads using a Standard dial-up connection and using a cable modem.

Identify the variable of interest in the study. -A doctor performs several diagnostic tests to determine the reason for a patient's illness.

Identify the variable of interest in the study. -Researchers at a university lab found that a genetically modified insect frog a toxin through its skin.

Identify the variable of interest in the study. -A T.V. show's executives raised the fee for commercials following a report that the show received a "No. 1" Rating in a survey of viewers.

Is the study experimental or observational? -A sample of fish is taken from a lake to measure the effect of pollution from a nearby factory on the fish.

Is the study experimental or observational? -A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided.

Is the study experimental or observational? -A marketing firm does a survey to find out how many people use a product. Of the one hundred people Contacted, fifteen said they use the product.

Identify the variable of interest in the study. -A quality control specialist compares the output from a machine with a new lubricant to the output of machines With the old lubricant.

Identify the variable of interest in the study. -An analysis of 10 individual studies attempted to determine if there is a conclusive link between "the Pill" and Ovarian cancer.

Identify the variable of interest in the study. -The highway department paves one section of an Interstate with Type A concrete and an adjoining section with Type B concrete and observes how long it takes until cracks appear in each.

Is the study experimental or observational? -The highway department paves one section of an Interstate with Type A concrete and an adjoining section with Type B concrete and observes how long it takes until cracks appear in each.

Is the study experimental or observational? -A clinic gives a drug to a group of ten patients and a placebo to another group of ten patients to find out if the Drug has an effect on the patients' illness.

Identify the variable of interest in the study. -An Information Technology Manager compares the average time required for 12 megabyte downloads using a Standard dial-up connection and using a cable modem.

Is the study experimental or observational? -A T.V. show's executives raised the fee for commercials following a report that the show received a "No. 1" Rating in a survey of viewers.

Identify the variable of interest in the study. -A sample of fish is taken from a lake to measure the effect of pollution from a nearby factory on the fish.