AnswersProbability and Statistics with Applications Honors Sem-1-FL-1210300 2024-2025Unit Test

Unit Test — Unit test Answers

25 verified answers2 views
1
Free Preview

A factory produces plastic parts used to fit in car dashboards. It is important that the parts are produced with the correct dimensions, or they may not fit in the car dashboard. To ensure that the parts are being made correctly, a sample of parts is checked and measured each day. Which of the following methods would not represent a convenience sample?

A
Right after lunch, the first 25 parts are inspected.
B
Fifty parts are chosen at random from the many parts made each day.
C
At the end of the day, a container of 30 parts is inspected and measured.
D
The first 20 parts produced after the start of the day are inspected and measured.
2
Free Preview

A veterinarian knows that the supplement glucosamine is beneficial for dogs’ joints. He wants to determine if a supplement with both glucosamine and chondroitin would be more beneficial than glucosamine alone for dogs’ joint health. The veterinarian asks the owners of dogs with known joint issues if they would be willing to have their dog participate in his study, and 32 owners agree to the study. The dogs’ names are written on equal-sized slips of paper. The veterinarian selects the first 16 slips of paper. These dogs are given the glucosamine treatment.. These dogs are given the glucosamine treatment. The other 16 dogs are given the glucosamine with chondroitin treatment. After six months, the dogs’ joint health is measured for each treatment and compared.

A
Yes, the treatments were randomly assigned to the dogs.
B
Yes, the treatment groups have the same number of dogs.
C
No, the veterinarian did not use dogs of the same breed.
D
No, the names were taken in order, so there was no randomization.
3

A company that manufactures golf balls produces a new type of ball that is supposed to travel significantly farther than the company’s previous golf ball. To determine this, 40 new-style golf balls and 40 original-style golf balls are randomly selected from the company’s production line on a specific day. The balls are then placed in a bag and shaken. A golf pro then selects a ball and hits it using a driver. The distance the ball travels is then measured. The bag is shaken again, and the golf pro selects another ball and hits it with the same driver. He continues this procedure until all 80 of the golf balls are hit.

A
Controlling the type of golf club used and having the same golf pro hit the ball eliminates the need to have a control group.
B
Controlling the type of golf club used and having the same golf pro hit the ball that may influence the response variable eliminates variability in the response variable.
C
Controlling the type of golf club used and having the same golf pro hit the ball that may influence the response variable reduces variability in the response variable.
D
Controlling the type of golf club used and having the same golf pro hit the ball means the differences observed in the response variable can be attributed to those variables that were controlled.
4

A restaurant critic for a newspaper examines the prices restaurants charge for their meals and discovers that the restaurants that raised their prices most over the past year also have the longest wait times for tables.

A
Increasing prices may cause customers to want to visit those restaurants more.
B
Restaurants that do not raise their prices may not see an increase in customers.
C
When customers wait longer for tables, they are more likely to pay higher prices.
D
Higher-quality restaurants might charge more for meals and could also have longer wait times.
5

A biologist wonders if the life span of bats will be affected by two new food sources from invasive species moving into an area. To conduct the experiment, the biologist needs three treatment groups: a group where the diet will not include invasive species (control), a group where the diet will include one invasive species (treatment group 1), and another group where the diet will include the other invasive species (treatment group 2). The biologist chooses the first cloud-free night and catches the first 18 bats that fly out of a cave, placing them into three equal groups of six bats. To decide the treatment for each group, the biologist places three slips of paper labeled control, treatment group 1, and treatment group 2 in a hat and randomly selects 2 slips of paper. The first piece of paper gives the treatment for the first group, the second piece of paper gives the treatment for the second group, and the remaining treatment is given to the third group.

A
The biologist did not use proper labeling on the pieces of paper.
B
The biologist did not use the appropriate number of treatment groups.
C
The biologist did not randomly assign the individual bats to the treatment groups.
D
The biologist did not randomly choose the weather on the night for bat capture.
6

A company that manufactures golf balls produces a new type of ball that is supposed to travel significantly farther than the company’s previous golf ball. To determine this, 40 new-style golf balls and 40 original-style golf balls are randomly selected from the company’s production line on a specific day. A golf pro randomly selects a ball, not knowing which type is chosen, and hits it. The difference in mean distances traveled (new – original) for the samples was 2.6 feet. Assuming there is no difference in distance traveled between the two types of golf balls, 200 simulated differences in sample means are displayed in the dotplot.

Question illustration
A
Yes, because a difference in mean distances of 2.6 feet or more occurred only 34 out of 200 times, meaning the difference is statistically significant. There is convincing evidence the new golf ball travels farther than the original golf ball.
B
Yes, because a difference in mean distances of 2.6 feet or less occurred 166 out of 200 times, meaning the difference is statistically significant. There is convincing evidence the new golf ball travels farther than the original golf ball.
C
No, because a difference in mean distances of 2.6 feet or more occurred 34 out of 200 times, meaning the difference is not statistically significant. There is not convincing evidence the new golf ball travels farther than the original golf ball.
D
No, because a difference in mean distances of 2.6 feet or less occurred 166 out of 200 times, meaning the difference is not statistically significant. There is not convincing evidence the new golf ball travels farther than the original golf ball.
7

Many golfers wear wrist bracelets containing magnets because they claim the magnets improve balance and the length of shots played off the tee. A golfer would like to determine if the claim has merit and finds 200 volunteers who play golf to participate in an experiment. Half of the golfers are randomly assigned to wear a bracelet with magnets, while the other half wear a bracelet without magnets. Each golfer plays normally for a month, after which the length of their shots in a subsequent round is recorded.

A
the age of each golfer
B
the 200 volunteers
C
the length of shots played by the golfers
D
whether the golfers wear or do not wear the bracelet
8

A teacher has 36 students who are sitting in 6 rows of 6 desks. He wants to survey the students about the homework policy. Which of the following uses cluster sampling?

A
Randomly assign the students to desks, and number the students 01–36. Use a random number table to generate a sample of students.
B
Randomly assign the students to desks. Number the rows 1 to 6. Use a random number table to select a number from 1 to 6, then survey every student in that row.
C
List all of the students alphabetically. Survey the 2nd person (with the number 2 being randomly chosen), then survey every 5th student after that.
D
List all of the students alphabetically. Survey 1 randomly chosen student whose last name begins with A, then continue the process through the alphabet.
9

A researcher is comparing the effectiveness of three devices designed to help people who snore. There are 210 people who snore participating in the experiment. Using a table of random digits starting from the first row and column, the researcher will randomly place the participants into three equally sized treatment groups suitable for comparison.

A
0–2
B
1–3
C
000–210
D
001–210
10

A study is testing the effectiveness of a new allergy medication. Sixty people who reported they experience allergies were randomly assigned to one of two groups: one with the new medication, and another with a placebo. After two weeks, the subjects were surveyed by technicians to determine their level of allergic symptoms.

A
This experiment should be double blind. Neither the subject nor the technician should know which group is receiving the new medication and which is receiving the placebo. This method would control for the placebo effect and prevent any effect on the response.
B
This experiment should be single blind. The subjects do not know which treatment they are receiving to control for the placebo effect, but the technicians need to know which group received which treatment.
C
This experiment should be single blind. The subjects know which treatment they are receiving but the technicians do not know which group received which treatment, so the response being measured is not affected.
D
This experiment should not use blinding. It is unethical for the subjects not to know which treatment they are receiving, placebo or new medication, and for the technicians not to know which group received which treatment.
11

A principal wanted to survey students who took a standardized college entry exam about how prepared they felt for the exam. The principal put together a bag of marbles. There was 1 marble for each student, and 20 of the marbles were red. Each student chose a marble, and those who chose the red marbles took the survey. Which sampling method was used?

A
cluster sampling
B
simple random sampling
C
stratified random sampling
D
systematic random sampling
12

City planners plan to survey residents to estimate the proportion of city residents who use public transportation at least once a week. Which of the following methods describes a voluntary response survey?

A
City planners stand outside an office building and survey workers.
B
City planners hand out surveys to parents at a youth soccer game.
C
City planners take a random sample of local homes and survey the residents.
D
City planners email a survey to all residents in the community.
13

A florist wants to determine if a new additive would help extend the life of cut flowers longer than the original additive. The florist randomly selects 20 carnations and randomly assigns 10 to the new additive and 10 to the original additive. After three weeks, 6 carnations placed in the new additive still looked healthy and 2 carnations placed in the original additive still looked healthy. The difference in proportions (new – original) for the carnations that still looked healthy after three weeks was 0.4. Assuming there is no difference in the additives, 200 simulated differences in sample proportions are displayed in the dotplot.

Question illustration
A
Yes, because a difference in proportions of 0.4 or more occurred 7 out of 200 times, meaning the difference is statistically significant and the new additive is more effective.
B
Yes, because a difference in proportions of 0.4 or less occurred 193 out of 200 times, meaning the difference is statistically significant and the new additive is more effective.
C
No, because a difference in proportions of 0.4 or more occurred 7 out of 200 times, meaning the difference is not statistically significant and the new additive is not more effective.
D
No, because a difference in proportions of 0.4 or less occurred 193 out of 200 times, meaning the difference is not statistically significant and the new additive is not more effective.
14

A greenhouse owner wants to test the effectiveness of a new fertilizer on African violets. She has 60 violet seedlings that were grown for 8 weeks. She wants to test the new fertilizer on 10 of the plants, and decides to use a simple random sample to select them. Which of the following statements is true?

A
She needs to select the 10 biggest plants to test the new fertilizer.
B
She needs to select the 10 smallest plants to test the new fertilizer.
C
She needs to number each plant 1–60 and randomly select 10 plants.
D
She needs to put the plants in 6 groups of 10 and randomly select 1 of the groups.
15

The CEO of a company wants to determine if taking the employees to a company retreat would boost their morale. He decides to use a random number table to survey a simple random sample of 50 of the 250 employees. Which of the following correctly labels the population of employees?

A
000–250
B
001–250
C
0–250
D
1–250
16

Research suggests that students could benefit from later school starting times. A school administrative team is considering a proposal to move the starting time of the local schools one hour later than the current start time. To measure interest in the proposal, members of the team randomly select subjects attending a large high school soccer tournament played on the high school grounds on a Saturday morning. The team finds that 58% of those surveyed support a later high school start time. Which type of bias is most likely to be present in the survey results?

A
This is undercoverage bias because adults with older children are more likely to be included in the sample.
B
This is question wording bias because the phrasing of the later start times question may be confusing to some subjects.
C
This is nonresponse bias because some of those selected may choose to not provide their opinion on later start times.
D
This is voluntary response bias because vocal supporters of later start times will be more likely to offer their opinion.
17

An automotive service center would like feedback on its customer service. Each customer receives a printed card after they pay for services with a short survey on which customer service is ranked on a scale from 1 (least satisfied) to 5 (most satisfied). Customers can then choose to submit the card in a box on their way out of the store. The store manager finds that 140 cards were filled out in the past week, with an average customer satisfaction score of 2.47. Which type of bias is most likely to be present in the survey results?

A
This is undercoverage bias because some types of customers may not have received cards.
B
This is nonresponse bias because many customers may choose to not fill out the cards.
C
This is question wording bias because the customer service score levels may not be clear to customers.
D
This is response bias because customers may not be truthful about their experience with customer service.
18

A biology student wants to determine if using a fertilizer would help promote growth of new babies in spider plants. The student has access to 90 spider plants of three varieties: green, variegated, and curly. They all are potted in the same amount and type of soil, given the same amount of water, and exposed to the same amount of light. After one year, the shoots will be counted for each plant.

A
The plants are numbered 01–90. Using a line from a random number table, the first 45 two-digit numbers, ignoring repeats and the numbers 91–99 and 00, represent the plants that will receive fertilizer. The remaining 45 plants will not receive fertilizer.
B
The plants are paired together based on similar size and numbered 1 and 2. Within each pair, a 6-sided number cube is rolled. If it lands on 1, 2, or 3, plant 1 receives the fertilizer and plant 2 does not receive fertilizer. If the cube lands on 4, 5, or 6, plant 1 does not receive fertilizer and plant 2 receives fertilizer. This is done for each of the 45 pairs of plants.
C
The plants are grouped based on variety. There are 30 plants of each variety. The plants within each variety are numbered 1–30, and the numbers are put in a random number generator. The first 15 unique numbers represent the plants in each variety that will receive fertilizer and the remaining 15 numbers will represent the plants in each variety that will not receive fertilizer.
D
The plants are grouped based on size. The 30 biggest plants are placed in one group and the 30 smallest plants in another other group. The remaining 30 plants are placed in a third group. For each group, a coin is flipped. If the coin lands on heads then the group will receive the fertilizer. If it lands on tails, then the group will not receive fertilizer. Repeat this procedure for the other two groups.
19

Many businesses and organizations insist that official communications use professional-looking fonts, such as Times New Roman. Fonts characterized as less professional, such as Comic Sans, should be avoided. A student would like to determine if font choice makes a difference in the average grade on a typed response in English classes. There are currently four English classes available from which the student can collect data, and each class has a similar writing assignment. The student considers two methods for collecting data.Method A: At the start of the assignment, students choose a font, either Times New Roman or Comic Sans, and then complete the assignment.Method B: At the start of the assignment, students are randomly assigned one of two fonts, either Times New Roman or Comic Sans, and then complete the assignment.In both methods, the teachers grade the papers received, and the mean grade for each font is determined.

A
Method A is an experiment because the students choose their own font.
B
Method B is an experiment because the students are randomly assigned a font.
C
Both methods describe experiments because both fonts are used on the assignment.
D
Neither method describes an experiment because a third font should be included for comparison.
20

A study is testing the effectiveness of a new allergy medication. Sixty people who reported they have allergies volunteered to be part of the study and were randomly assigned to one of two groups, as shown in the design web.Which of the following accurately describes the benefit of comparison in the experiment shown in the design web?

Question illustration
A
The level of allergic symptoms in both groups can be compared to see if the new medication had a significant effect.
B
The overall level of allergic symptoms can be used to determine if the new allergy medication had a significant effect.
C
The level of allergic symptoms in the group who received the medication can be used to determine if the medication had a significant effect.
D
The level of allergic symptoms in both groups cannot be compared to determine if the medication had a significant effect because one group only received a placebo.

Did you find these answers helpful?

More from this Course

Quiz
15 verified answers

Unit Test

RC
25 verified answers

Cumulative Exam

Quiz
49 verified answers

Cumulative Exam

Unit Test — Unit test Answers — Probability and…