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Elementary Statistics Chapter 1 Test - Form A
Name:___________________________ Course Number: __________ Section Number: _____
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Provide an appropriate response.
- Define the terms population, sample, parameter and statistic. How does a census compare to a sample?
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Identify the number as either continuous or discrete.
The total number of phone calls a sales representative makes in a month is 425. A) Continuous B) Discrete
The number of limbs on a 2-year-old oak tree is 21. A) Continuous B) Discrete
Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate.
The subjects in which college students major. A) Ratio B) Ordinal C) Nominal D) Interval
Amount of fat (in grams) in cookies. A) Nominal B) Interval C) Ordinal D) Ratio
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Identify the sample and population. Also, determine whether the sample is likely to be representative of the population.
- In a poll of 50,000 randomly selected college students, 74% answered "yes" when asked "Do you have a television in your dorm room?".
Use critical thinking to develop an alternative conclusion.
- A study shows that adults who work at their desk all day weigh more than those who do not. Conclusion: Desk jobs cause people to gain weight.
Use critical thinking to address the key issue.
A questionnaire is sent to 10,000 persons. 5,000 responded to the questionnaire. 3,000 of the respondents say that they "love chocolate ice cream". We conclude that 60% of people love chocolate ice cream. What is wrong with this survey?
A researcher wished to gauge public opinion on gun control. He randomly selected 1000 people from among registered voters and asked them the following question: "Do you believe that gun control laws which restrict the ability of Americans to protect their families should be eliminated?". Identify the abuse of statistics and suggest a way the researcher's methods could be improved.
Elementary Statistics Chapter 1 Test - Form A MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Perform the requested conversions. Round decimals to the nearest thousandth and percents to the nearest tenth of a percent, if necessary.
- Convert 0.34 to an equivalent fraction and percent. A) 8 25
, 34% B)^8
, 3.4% C)^17
, 3.4% D)^17
Solve the problem.
- A gardener has 28 clients, 25% of whom are businesses. Find the number of business clients. A) 7000 clients B) 700 clients C) 7 clients D) 70 clients
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. A) Experimental B) 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. A) Observational B) Experimental
Identify the type of observational study.
- A statistical analyst obtains data about ankle injuries by examining a hospital's records from the past 3 years. A) Retrospective B) Cross-sectional C) Prospective D) None of these
Identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience.
A tax auditor selects every 1000th income tax return that is received. A) Random B) Systematic C) Convenience D) Cluster E) Stratified
A pollster uses a computer to generate 500 random numbers, then interviews the voters corresponding to those numbers. A) Stratified B) Cluster C) Convenience D) Systematic E) Random
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Provide an appropriate response.
- Define random sample. Explain why this is important in design of experiments.
Answer Key
Testname: ELEMENTARY STATISTICS CHAPTER 1 TEST FORM A
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
A population is the complete collection of all elements. A sample is a subset of elements drawn from a population. A parameter is a numerical measurement describing some characteristic of a population. A statistic is a numerical measurement describing some characteristic of a sample. A census is the collection of data from every element in a population; a sample is a subset of a population. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
B
B
C
D SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Sample: the 50,000 selected college students; population: all college students; representative
Desk job workers are confined to their chairs for most of their work day. Other jobs require standing or walking around which burns calories. It is probably the lack of exercise that causes higher weights, not the desk job itself. Avoid causality altogether by saying lack of walking and exercise is associated with higher weights.
This is not a random sample. The survey is based on voluntary, self-selected responses and therefore has serious potential for bias.
The question is loaded. A more neutral way to phrase the question would be, for example, "Do you believe that gun control laws should be strengthened, weakened, or left in their current form?". MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
D
C
B
B
A
B
E SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
In random sampling, each member of the population has an equal chance of being selected. Random sampling provides us with the best representative sample in which all groups of the population are approximately proportionately represented. Careless sampling can easily result in a biased sample which may be useless.
Sampling error is the difference between a sample result and the true population result. Such an error results from chance sample fluctuations. A nonsampling error occurs when the sample data are incorrectly collected, recorded, or analyzed. Examples include nonrandom samples, defective measuring instruments, biased survey questions, a large number of refusals, copying sample data incorrectly.
This is systematic sampling. The sample obtained will be a random sample because everyone has the same chance of being chosen but will not be a simple random sample as different samples of 50 people have different chances of being chosen. Specifically, the sample is random because each person has one chance in twenty of being selected. The sample is not simple random because different samples of size 50 by this design have different chances of being selected due to the numbers of people arriving at the store at different times.
Answer Key
Testname: ELEMENTARY STATISTICS CHAPTER 1 TEST FORM A
- In both cluster sampling and stratified sampling, sub-groups (clusters or strata) are formed. However, in stratified sampling, all strata are used and a sample is selected from each strata. In cluster sampling, a sample of the clusters is first selected, then all members of those clusters are selected.
Elementary Statistics Chapter 1 Test - Form B MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Perform the requested conversions. Round decimals to the nearest thousandth and percents to the nearest tenth of a percent, if necessary.
- Convert 8.4% to an equivalent fraction and decimal. A) 2 25
, 0.84 B)^21
, 0.84 C) 2
, 0.084 D) 21
Solve the problem.
- Alex and Juana went on a 120-mile canoe trip with their class. On the first day they traveled 30 miles. What percent of the total distance did they canoe? A) 4% B) 0.25% C) 25% D) 400%
Is the study experimental or observational?
A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided. A) Experimental B) Observational
A T.V. show's executives commissioned a study to gauge the impact of the show's ratings on the sales of its advertisers. A) Observational B) Experimental
Identify the type of observational study.
- A researcher plans to obtain data by following those in cancer remission since January of 2002. A) Cross-sectional B) Retrospective C) Prospective D) None of these
Identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience.
A sample consists of every 49th student from a group of 496 students. A) Stratified B) Random C) Cluster D) Systematic E) Convenience
The name of each contestant is written on a separate card, the cards are placed in a bag, and three names are picked from the bag. A) Cluster B) Random C) Stratified D) Convenience E) Systematic
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Use critical thinking to address the key issue.
- "7 out of 10 dentists recommend Brand X toothpaste". This finding is based on the results of a survey of 10 randomly selected dentists. What is wrong with this survey?
Elementary Statistics Chapter 1 Test - Form B Provide an appropriate response.
List five different abuses of statistics and give examples for each.
A teacher at a school obtains a sample of students by selecting a random sample of 20 students from each grade. What kind of sampling is being used here? Will the resulting sample be a simple random sample of the population of students at the school? Explain your thinking.
At a school there are two different math classes of the same age. The two classes have different teachers. The school principal is interested in gauging the effectiveness of two different teaching methods and asks each teacher to try one of the methods. At the end of the semester both classes are given the same test and the results are compared. In this experiment, what is the variable of interest? Give some examples of variables which could be confounding variables.
Elementary Statistics Chapter 1 Test - Form C
Name:___________________________ Course Number: __________ Section Number: _____
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Provide an appropriate response.
- Define continuous and discrete data and give an example of each.
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Determine whether the given value is a statistic or a parameter.
A health and fitness club surveys 40 randomly selected members and found that the average weight of those questioned is 157 lb. A) Statistic B) Parameter
After inspecting all of 55,000 kg of meat stored at the Wurst Sausage Company, it was found that 45,000 kg of the meat was spoiled. A) Statistic B) Parameter
Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate.
Salaries of college professors. A) Ratio B) Ordinal C) Interval D) Nominal
Survey responses of "good, better, best". A) Ordinal B) Ratio C) Interval D) Nominal
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Identify the sample and population. Also, determine whether the sample is likely to be representative of the population.
- An employee at the local ice cream parlor asks three customers if they like chocolate ice cream.
Use critical thinking to address the key issue.
You plan to make a survey of 200 people. The plan is to talk to every 10th person coming out of the school library. Is there a problem with your plan?
A national television channel posted the result of their web poll: "63 percent of Americans favor changing from gasoline to hydrogen fuel for cars." The survey question had been available for three days and 50,000 viewers responded. Should we conclude that hydrogen-powered cars are favored by a majority of Americans? Explain.
A company accused of downsizing workers defended itself with the following statement: "Yes, we were forced to lay off 20% of our workforce last year, but this year we increased our workforce by 20%, and we therefore now have the same number of employees as before the layoff." What is the flaw in this argument?
Elementary Statistics Chapter 1 Test - Form C MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Perform the requested conversions. Round decimals to the nearest thousandth and percents to the nearest tenth of a percent, if necessary.
- Convert 1.2 to an equivalent fraction and percent. A) 1^1 10
, 12% B) 1^1
, 120% C) 1^1
, 12% D) 1^1
Solve the problem.
- On a test of 80 items, Ariel got 68 correct. What percent were correct? A) 117.647059% B) 1.17647059% C) 0.85% D) 85%
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. A) Experimental B) 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. A) Experimental B) Observational
Identify the type of observational study.
- A town obtains current employment data by polling 10,000 of its citizens this month. A) Prospective B) Retrospective C) Cross-sectional D) None of these
Identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience.
A market researcher selects 500 drivers under 30 years of age and 500 drivers over 30 years of age. A) Cluster B) Systematic C) Stratified D) Random E) Convenience
A researcher interviews 19 work colleagues who work in his building. A) Stratified B) Random C) Cluster D) Systematic E) Convenience
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Provide an appropriate response.
- Describe a double blind experiment and explain why blinding is used. Define the term "placebo effect" as part of the answer.
Answer Key
Testname: ELEMENTARY STATISTICS CHAPTER 1 TEST FORM C
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Continuous numerical data result from infinitely many possible values that can be associated with points on a continuous scale so that there are no gaps or interruptions. Discrete data result from either a finite number of possible values or a countable number of possible values. Examples will vary. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
A
B
A
A SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Sample: the 3 selected customers; population: all customers; not representative
People who don't go to the library are excluded.
This is not a random sample. The survey is based on voluntary, self-selected responses and therefore has serious potential for bias, because the result should not be generalized to all Americans.
Answers will vary. Possible answer: This is a misleading use of percentages, as 20% of the reduced workforce is smaller than 20% of the original workforce. The company therefore did not hire as many new workers as it originally laid off. The size of the current workforce is therefore smaller than the size of the workforce before the layoffs. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
B
D
A
B
C
C
E SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
A double blind experiment is one in which neither the subjects nor the researchers know who is getting the treatment. Blinding is when the subject does not know whether he or she is receiving a treatment or a placebo. Blinding is used to counteract the placebo effect in which an untreated subject believes he or she is receiving a treatment and reports an improvement in symptoms due to this belief.
In an observational study, we observe and measure specific characteristics, but we don't attempt to manipulate or modify the subjects being studied. In an experiment we apply some treatment and then proceed to observe its effects on the subjects. In the experiment, the group receiving the treatment is called the treatment group. The control group is the group that is not given the treatment.
This is cluster sampling. The sample obtained will not be a simple random sample of all high school teachers in the district because different samples have different chances of being selected due to varying numbers of teachers in different schools.
Confounding occurs in an experiment when the effects of two or more variables cannot be distinguished from each other. Examples will vary.
Elementary Statistics Chapter 2 Test - Form A
Name:___________________________ Course Number: __________ Section Number: _____
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Identify as many similarities and differences that you can find.
Suppose that a data set has a minimum value of 28 and a maximum value of 73 and that you want 5 classes. Explain how to find the class width for this frequency distribution. What happens if you mistakenly use a class width of 9 instead of 10?
A company advertises an average of 42,000 miles for one of its new tires. In the manufacturing process there is some variation around that average. Would the company want a process that provides a large or a small variance? Justify your answer.
Use the range rule of thumb to solve the problem.
- The data shows the roundtrip mileage that 43 randomly selected professors and students drive to school each day. Graph the frequency polygons and determine whether there appears to be any significant difference between the two groups.
Score Frequency 10- 15- 20- 25- 30-
Score Frequency 10- 15- 20- 25- 30-
5 10 15 20 25 30 35 40
18 16 14 12 10 8 6 4 2
5 10 15 20 25 30 35 40
18 16 14 12 10 8 6 4 2
Elementary Statistics Chapter 2 Test - Form A Use the range rule of thumb to solve the problem.
- 100 casino patrons, were interviewed as they left the casino. 30 of them said they spent most of the time playing the slots. 30 of them said they played blackjack. 15 said they played craps. 5 said roulette. 5 said poker. The rest were not sure what they played the most. Select the Pareto chart that displays these findings. A) B)
C) D)
Find the mean of the data summarized in the given frequency distribution.
- A company had 80 employees whose salaries are summarized in the frequency distribution below. Find the mean salary.
Salary ($) Employees 5,001-10,000 18 10,001-15,000 20 15,001-20,000 20 20,001-25,000 14 25,001-30,000 8 A) $14,287.95 B) $17,500 C) $15,875.50 D) $17,463.
Elementary Statistics Chapter 2 Test - Form A Find the range for the given data.
- Fred, a local mechanic, gathered the following data regarding the price, in dollars, of an oil and filter change at twelve competing service stations: 32.95 24.95 26.95 28. 18.95 28.95 30.95 22. 24.95 26.95 29.95 28. Compute the range. A) $12 B) $10 C) $8 D) $
Find the variance for the given data. Round your answer to one more decimal place than the original data.
- Compute the variance. The owner of a small manufacturing plant employs six people. As part of their personnel file, she asked each one to record to the nearest one-tenth of a mile the distance they travel one way from home to work. The six distances are listed below: 52 38 15 24 15 39 A) 222.7 B) 38.9 C) 32.5 D) 167.
Find the standard deviation for the given data. Round your answer to one more decimal place than the original data.
- To get the best deal on a CD player, Tom called eight appliance stores and asked the cost of a specific model. The prices he was quoted are listed below: $249 $195 $162 $446 $279 $214 $307 $ Compute the standard deviation s. A) $578,041.0 B) $91.3 C) $233.0 D) $519,690.
Use the range rule of thumb to solve the problem.
- The heights in feet of people who work in an office are as follows. Use the range rule of thumb to estimate the standard deviation. Round results to the nearest tenth. 5.7 6.0 5.8 5.4 5.6 6.0 5.5 6.2 6.0 6.0 5.5 5.8 5.6 5.7 5.9 6.0 6.1 5.5 5.7 6. A) 1.2 B) 0.1 C) 0.2 D) 0.
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Use the range rule of thumb to solve the problem.
- Weekly sales for the Dade Company average $10,000 with a standard deviation of $450. During a recent week sales were $9050. Is that amount unusually low? Why or why not?
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Solve the problem. Round results to the nearest hundredth.
- A department store, on average, has daily sales of $28,176.44. The standard deviation of sales is $
- On Tuesday, the store sold $34,083.30 worth of goods. Find Tuesday's z score. Was Tuesday an unusually good day? A) 4.25, yes B) 3.94, yes C) 4.13, no D) 3.15, no
Answer Key
Testname: ELEMENTARY STATISTICS CHAPTER 2 TEST FORM A
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
- For the given data, the class width is 9, since that value is the range, 73 - 28, divided by the number of classes. However, the quotient should always be rounded up, even when a whole number results. If 9 were mistakenly used as the class width, the last datum, which is 73, would be cut off the distribution because the upper limit of the fifth class is 72. More data would be cut off, if the class start was below
- Answers will vary.
- There does not appear to be a significant difference.
5 10 15 20 25 30 35 40 45 50 55 60 score
(^24) freq 22 20 18 16 14 12 10 8 6 4 2 5 10 15 20 25 30 35 40 45 50 55 60 score
(^24) freq 22 20 18 16 14 12 10 8 6 4 2
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
A
B
C
A
A
B
C
D
A
B
C SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
Yes, $9050 is unusually low because it is less than $9100, which is two standard deviations below the mean. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
B
C
B
A
Answer Key
Testname: ELEMENTARY STATISTICS CHAPTER 2 TEST FORM A
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
- Let the boxplot on the left represent distribution A; boxplot on the right, distribution B. Distribution A is uniform; distribution B is skewed to the left. Distribution A has a higher maximum value. Distribution B has a lower minimum value. The median of distribution B exceeds that of A. Both interquartile ranges are the same, implying the variation among the middle 50% of values of each distribution is the same. There are no outliers for either distribution, but distribution B shows more variation.
