On all free response questions, round all answers to 3 decimal places (if necessary). You may use any calculator functions you want, but show all required work as demonstrated in class. !1. A school psychologist wants to test the effectiveness of a new method for teaching reading. She

recruits 500 first-grade students in District 203 and randomly divides them into two groups.

Group 1 is taught by means of the new method, while group 2 is taught by traditional methods.

The same teacher is assigned to teach both groups. At the end of the year, an achievement test is

administered and the results of the two groups are compared.

(a) What are the experimental units?

(b) What is the response variable in this experiment?

(c) What are the treatments? How many treatments are there?

(e) Which group serves as the control group?

All students in the experiment Achievement test results Two methods of teaching are the two treatments - traditional and new method Group 2 – receiving the traditional teaching method

Math 203: Exam 1 Practice Test Solutions (Chapters 1-3)

2. A cellular phone company is looking for ways to improve customer satisfaction. They want to

select a simple random sample of four stores from their 15 franchises in which to conduct

customer satisfaction surveys. The locations are as follows:

Using the random digit table provided below with a seed of row 2 column 3, select a simple random sample of size n = 4. List the locations members below.

Selected Locations:

3. A random sample of couples married for 7 years were asked to give the number of children they

have. The results of the survey are as follows:

!(a) Construct a frequency distribution of the data.

(b) Construct a relative frequency distribution of the data.

(c) Construct a cumulative frequency distribution of the data.

(d) Construct a cumulative relative frequency distribution of the data.

(e) Construct a frequency histogram of the data. Describe the shape of the distribution.

(g) What percentage of couples married 7 years has two children?

(h) What percentage of couples married 7 years has at least two children?

4. The following is a USA Today type graph based on data from the Department of Agriculture. It

represents the percentage of income a middle-income family will spend on their children.

(a) How is the graphic misleading?

(b) What could be done to improve the graphic?

bars are not drawn to scale-the bar of 33% of the data appears to cover 80% of the graph. The length of bars in the 33% and 18% are not proportionate. 33% is almost double the value of 18% while the bar is only slightly longer.

Make the length of bars proportionate to the data value and each other. Make the length of bars proportionate in scale to the entire graph.

bars are not drawn to scale-the bar of 33% of the data appears to cover 80% of the graph. The length of bars in the 33% and 18% are not proportionate. 33% is almost double the value of 18% while the bar is only slightly longer.

Source: Christenson, Ronald, and Blackwood, Larry, “Tests for Precision and Accuracy of Multiple Measuring Devices,” Technometrics.

(a) Compute the sample mean, five number summary, and range of the muzzle velocity.

(b) Compute the sample variance and sample standard deviation of the muzzle velocity.

On all free response questions, round all answers to 3 decimal places (if necessary). You may use any calculator functions you want, but show all required work/drawing as demonstrated in class, including what you input in your calculator when applicable.

1. The following data represent the muzzle velocity (in meters per second) of rounds firedfrom a 155-mm gun.

5. The following data represent the muzzle velocity (in meters per second) of rounds fired from a 155-mm gun.

random sample of Stats students yelled at MyMathLab while taking a quiz online.

Source: This is made-up. I hope this is not true ☺

Approximate the standard deviation of the time spent yelling at MyMathLab.

6. The frequency distribution listed in the table represents the amount of time (in minutes) a

b. What percentage of people has an IQ score between 70 and 130?

c. What percentage of people has an IQ score less than 70 or greater than 130?

d. What percentage of people has an IQ score between 85 and 145?

bell-shaped distribution with a mean of 100 and a standard deviation of 15.

a. Sketch the appropriate curve used with the Empirical Rule. Label the key values on the x-

axis as well as the percentages of data in each section of the graph as demonstrated in class.

7. One measure of intelligence is the Stanford–Binet Intelligence Quotient (IQ). IQ scores have a

Multiple Choice Questions PartMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) In a small town, 84% of the residents, aged 16 or more years old, own a car. Is this anexample of statistic or a parameter?

1)

A) Statistic B) Parameter

2) Of the televisions offered at an electronics store, 42% cost less than $500.00. Is this anexample of statistic or a parameter?

2)

A) Statistic B) Parameter

3) A middle school student passes out leaflets to the adults at a school function. The leafletsask the recipient to indicate whether they believe in anthropogenic global warming. Thebottom of the leaflet indicates that the completed leaflet should be returned to thestudent. Identify the kind of sample that is being used.

3)

A) cluster sample B) sample of convenienceC) systematic sample D) stratified sample

4) An electronics manufacturer test every 50th cell phone to verify that it is functioningproperly. Identify the kind of sample that is being used.

4)

A) cluster sample B) systematic sampleC) simple random sample D) stratified sample

5) The names of all 126 students in a professor's class are written on identical slips ofpaper, and the slips are placed into a large glass jar. Then, the professor selects 14random slips from the jar. Identify the kind of sample that is being used.

5)

A) systematic sample B) cluster sampleC) simple random sample D) sample of convenience

6) Determine which of the following describes quantitative data.i). the name of a chemical sampleii). the mass of a chemical sampleiii). the color of a chemical sample

6)

A) i and ii only B) i, ii, and iii C) ii only D) i only

7) Determine which of the following describes qualitative data.i). the volume of a shipping container, in gallonsii). the name of the material from which the container is madeiii). the shape of the container

7)

A) i and ii only B) i, ii, and iii C) i and iii only D) ii and iii only

1

8) Determine which of the following describes qualitative data.i). the make of the car with license plate number VNS-862ii). the license plate number VNS-862iii). the number of vehicles whose license plate number begins with "VNS"

8)

A) neither i, nor ii, nor iii B) iii onlyC) i and ii only D) i only

9) Determine which of the following describes nominal data.i. Michaelangelo's sells small, medium, large, and jumbo pizzas.ii. Michaelangelo's most-requested toppings are pepperoni, black olives, and mushrooms.

9)

A) neither i nor ii B) ii only C) i only D) both i and ii

10) Determine which of the following describes ordinal data.i. In the horse race, Betty's Girl won, Mr. Ed placed, and Wabash showed.ii. In the horse race, I bet on Betty's Girl to win, Mr. Ed to place, and Wabash to show.

10)

A) neither i nor ii B) ii only C) both i and ii D) i only

11) Which one of the following data are discrete? 11)A) the number of crew members on the boatB) the latitude and longitude of a boat at seaC) the latitude and longitude of the boat's port of departureD) the speed of the boat's propeller, in revolutions per minute

12) Which one of the following data are continuous? 12)A) the average height of a sample of treesB) the number of species of trees in a parkC) the number of representatives of each species in the parkD) the rankings of the trees, from most numerous to least numerous

13) Which one of the following data are continuous? 13)A) all of these represent continuous dataB) the number of musicians performing in the MP3 fileC) the time remaining for an MP3 music downloadD) the number of times the file has been downloaded

14) When experimental units are people, they are sometimes called ________________. 14)A) personnel B) human units C) topics D) subjects

15) Which of the following is the best description of a randomized experiment? 15)A) an experiment in which the outcomes are randomB) an experiment in which the experimental units are selected at randomC) an experiment in which the investigators are chosen at random

D) an experiment in which the treatments are assigned randomly to experimental units

2

16) Which of the following is the best description of a double-blind experiment? 16)A) an experiment in which the subjects are blindfolded so they cannot see which

treatment is applied to themB) an experiment in which neither the investigators nor the subjects know the others'

namesC) an experiment in which both the investigators and the subjects are hidden from the

others' viewsD) an experiment in which neither the investigators nor the subjects know how the

treatments have been assigned

17) An experiment that tends to overestimate or underestimate the true value is said to be______________.

17)

A) un-randomized B) flagrantC) randomized D) biased

18) The question..."Do you favor a higher standard of living, even though it produces unclean air and water?"

... is an example of ...

18)

A) sampling bias B) random samplingC) leading question bias D) framing

19) A small brew pub sent out questionnaires to a simple random sample of 250 customersasking whether they would like the brewery to include an imperial stout in their regularofferings. Of the 250 questionnaires, 12 were returned and 10 of those were in favor ofincluding the stout. Specify the type of bias involved.

19)

A) Voluntary response B) SamplingC) Self-interest D) Nonresponse

20) The following bar graph presents the average amount a certain family spent, in dollars, on variousfood categories in a recent year.

On which food category was the most money spent?

20)

A) Cereals and baked goods B) Dairy productsC) Meat poultry, fish, eggs D) Fruits and vegetables

3

21) The following pie chart presents the percentages of fish caught in each of four ratings categories.

Match this pie chart with its corresponding Pareto chart.

21)

A)

B)

4

C)

D)

22) The following frequency distribution presents the frequency of passenger vehicles that passthrough a certain intersection from 8:00 AM to 9:00 AM on a particular day.

Vehicle Type FrequencyMotorcycle 5

Sedan 75SUV 70Truck 35

Construct a frequency bar graph for the data.

22)

A)

5

B)

C)

D)

23) Classify the histogram as skewed to the left, skewed to the right, or approximately symmetric.23)

A) approximately symmetricB) skewed to the rightC) skewed to the left

6

24) The following frequency distribution presents the weights in pounds (lb) of a sample of visitors toa health clinic.

Weight (lb) Frequency100-103 2104-107 1108-111 4112-115 4116-119 10120-123 9124-127 4128-131 1

What is the class width?

24)

A) 4 B) 32 C) 5 D) 3

25) Construct a stem-and-leaf plot for the following data. 25)

A) B)

C) D)

7

26) The amounts 3 and 2 are compared. Which of the following graphical displays are theleast misleading?

26)

A)

B)

C)

D)

8

27) Gravity on Mars: The gravity on Earth is around 23

's stronger than the gravity on Mars.

Which of the following graphics compare the gravity differences more accurately, and why?

27)

A) B)

28) Find the median for the following data set:

12 13 20 15 23

28)

A) 16.6 B) 4.2 C) 15 D) 11

29) A report states that the mean household income last year for a certain rural county was$46,200 and the median was $37,800. If a histogram were constructed for the incomes ofall households in the county, would you expect it to be skewed to the right, to the left, orapproximately symmetric?

29)

A) approximately symmetricB) skewed to the rightC) skewed to the left

30) Find the population variance for the following data set:

27 13 28 32 20

30)

A) 7.5 B) 45.2 C) 19 D) 56.5

31) The completion times for a certain marathon race was 2.4 hours with a standarddeviation of 0.5 hours. What can you determine about these data by using Chebyshev'sInequality with K = 2?

31)

A) At most 88.9% of the completion times are between 1.4 hours and 3.4 hours.B) At least 75% of the completion times are between 1.4 hours and 3.4 hours.C) At least 88.9% of the completion times are between 1.4 hours and 3.4 hours.D) No more than 75% of the completion times are between 1.4 hours and 3.4 hours.

9

32) A population has a mean = 46 and standard deviation = 15. Find the z-score for apopulation value of 13.

32)

A) -33 B) -2.2 C) 0.9 D) -0.5

33) For the data set below, find the first quartile. 33)

A) 76 B) 48.5 C) 65 D) 60

34) For the data set below, find the IQR. 34)

A) 64 B) 17 C) 74 D) 10

35) For the data set below, find the upper outlier boundary. 35)

A) 243.5 B) 45 C) 195 D) 176

36) For the data set below, find the outlier(s). 36)

A) 141 and 150 B) 189C) 141 and 189 D) None are outliers.

37) The mean salary of professional baseball players is $2.58 million with a standarddeviation of 0.33. A new player is hired with a salary of $2.76 million. What is thez-score of this salary?

37)

A) 16.18 B) 8.36 C) -16.18 D) 0.55

10

1) B2) B3) B4) B5) C6) C7) D8) C9) B

10) C11) A12) A13) C14) D15) D16) D17) D18) C19) D20) B21) B22) B23) A24) A25) B26) C27) A28) C29) B30) B31) B32) B33) C34) D35) A36) C37) D

11

Answer Keys to Multiple Choice Questions Part