PRINTABLE VERSION - UHcathy/Math2311/Lectures/may23.pdf · A real estate agent would like to predict the selling price of a single-family house by predicting the price (in thousands

5/17/2018 Print Test

https://assessment.casa.uh.edu/Assessment/PrintTest.htm 5/6

a) 0.7210

b) 0.0569

c) 0.4790

d) 0.2790

e) 0.5580

f) None of the above

Question 13

Suppose that a random sample of size 25 is to be selected from a population with mean 44 and standarddeviation 7. What is the approximate probability that X will be more than 0.5 away from the populationmean?

a) 0.2790

b) 0.0569

c) 0.4790

d) 0.7210

e) 0.5580


Question 14

Lloyd's Cereal company packages cereal in 1 pound boxes (16 ounces). A sample of 64 boxes is selected atrandom from the production line every hour, and if the average weight is less than 15 ounces, the machine isadjusted to increase the amount of cereal dispensed. If the mean for 1 hour is 1 pound and the standarddeviation is 0.2 pound, what is the probability that the amount dispensed per box will have to be increased?

a) 0.9938

b) 0.3773

c) 0.2062

d) 0.0062

e) 0.0124




Question 15

In a large population, 92% of the households have cable tv. A simple random sample of 64 households is tobe contacted and the sample proportion computed. What is the mean and standard deviation of the samplingdistribution of the sample proportions?

a) mean = 0.92, standard deviation = 1.2739

b) mean = 0.92, standard deviation = 0.0012

c) mean = 0.92, standard deviation = 0.0339

d) mean = 58.88, standard deviation = 0.0339

e) mean = 58.88, standard deviation = 0.0012


Question 16

In a large population, 67% of the households have cable tv. A simple random sample of 256 households is tobe contacted and the sample proportion computed. What is the probability that the sampling distribution ofsample porportions is less than 73%?

a) 0.0206

b) 0.4897

c) 0.9794

d) 0.8796

e) 0.1204




PRINTABLE VERSIONQuiz 7

Question 1

Which of the following would be the scatterplot for the given data?

x 4 7 8 12 14 18 y 21 29 29 42 28 41

a)



b)

c)



d)

e) None of the above

Question 2

What can be said about the relationship between the explantory variable and the response variable in thefollowing scatterplot?



a) There is a strong negative linear association.

b) There is a strong positive linear association.

c) There is a weak positive linear association.

d) The explanatory variable causes the responses.


Question 3

Determine the correlation coefficient for the data shown in this table:

x 3 8 10 14 16 17 y 43 37 28 22 20 12

a) -0.9751

b) -0.9508

c) 0.9508

d) 0.9751

e) -0.4875


Question 4

Choose the best correlation coefficient for the data shown in this scatterplot:



a) -0.9028

b) -0.4514

c) -1.7058

d) 0.4514

e) 0.9028

Question 5

Which of the following is a true statement?

a) A negative correlation indicates that as values of x decrease, values of y will decrease.

b) The coefficient of determination can never assume negative values.

c) If there is no correlation between the independent and dependent variables, then the value of thecorrelation coefficient must be -1.

d) The correlation coefficient r is always greater than 1.

e) The variable that is being predicted in regression analysis is the independent variable.




Question 6

The decline of salmon fisheries along the Columbia River in Oregon has caused great concern amongcommercial and recreational fishermen. The paper 'Feeding of Predaceous Fishes on Out-Migrating JuvenileSalmonids in John Day Reservoir, Columbia River' (Trans. Amer. Fisheries Soc. (1991: 405-420)) gave theaccompanying data on y = maximum size of salmonids consumed by a northern squaw fish (the mostabundant salmonid predator) and x = squawfish length, both in mm. Use the following statistics to give theequation of the least squares regression line.

x = 525.060, y = 319.607, sx = 17.908, sy = 14.300, r = 0.9768

a) ŷ = 1.223x − 89.940

b) ŷ = 1.223x + 89.940

c) ŷ = -89.940x + 0.780

d) ŷ = 0.780x + 89.940

e) ŷ = 0.780x − 89.940


Question 7

Suppose that you are given the following results. Find the correlation coefficient of the data.

sx = 4.866, sy = 11.100, b = -1.800

a) -0.789

b) 0.789

c) -0.395

d) -0.267

e) 0.267


Question 8

Suppose you find that the correlation coefficient for a set of data is 0.855. What is the coefficient ofdetermination and what does it mean?

a) 0.855; This means that we are 85.5% accurate with our prediction of the LSRL equation.



b) 0.731; This means that we are 73.1% accurate with our prediction of the LSRL equation.

c) 0.855; This means that 85.5% of the variation of y is explained by the LSRL of y on x.

d) 0.731; This means that 73.1% of the variation of y is explained by the LSRL of y on x.


Question 9

A real estate agent would like to predict the selling price of a single-family house by predicting the price (inthousands of dollars) based on the square footage (in 100 square feet). If the LSRL for the data is ŷ =3.8785x + 18.3538, predict the price of a 3000 square foot house (in thousands of dollars).

tbl

a) 139.709

b) 242.709

c) 134.709

d) 252.709

e) 673.544


Question 10

Select the equation of the least squares line for the data: (51.00, 1.0), (48.75, 2.5), (52.50, .5), (46.50, 5.0),(45.00, 4.5), (41.25, 6.5), (43.50, 5.0).

a) ŷ = 28.956 − 0.59474x

b) ŷ = 31.852 − 0.59474x

c) ŷ = 0.54067x − 28.956

d) ŷ = -28.956 − 0.54067x

e) ŷ = 28.956 − 0.54067x





Question 1

Which of the following would be the LSRL for the given data?

x 5 5 11 12 15 19 y 41 37 28 21 17 14

a) ŷ =

b) ŷ =

c) ŷ =

d) ŷ =


Question 2

Determine the correlation coefficient for the data shown in this table:

x 1 8 9 12 17 20 y 41 38 28 20 18 14

a) -0.9352

b) 0.9352

c) 0.8746

d) -0.8746

e) -0.4676


Question 3

Suppose you have the following data:



x 1 2 3 4 5 6 y 44 37 27 21 22 14

and the LSRL is ŷ = . Find the residual value for x = 1.

a)

b)

c)

d)


Question 4

Which of the following is the residual plot for the data in the given table?

x 1 2 3 4 5 6 y 16 20 18 31 24 32

a)



b)

c)



d)


Question 5

Which of the following residual plots would indicate a good LSRL model?

a)



b)

c)



d)

Question 6

For children between the ages of 18 months and 29 months, there is approximately a linear relationshipbetween height and age. The relationship can be represented by ŷ = 62.55 + 0.62x where y represents height(in centimeters) and x represents age (in months). Joseph is 23.5 months old and is 80 centimeters tall. Whatis Joseph's residual?

a) 2.880

b) 77.120

c) 7.880

d) 112.150

e) -32.150


Question 7

If the LSRL relating the independent variable x and the dependent variable y for a given problem is ŷ = 2x +4, then an increase of 1 unit in x is associated with an increase of how many units in y?

a) 6

b) 0



c) 2

d) 1

e) 4

Question 8

If the correlation between body weight and annual income were high and positive, we could conclude that:

a) high incomes cause people to eat more food.

b) high-income people tend to spend a greater proportion of their income on food than low-incomepeople.

c) high incomes cause people to gain weight.

d) high-income people tend to be heavier than low-income people.

e) low incomes cause people to eat more food.

Question 9

The following two-way table describes the preferences in movies and fast food restaurants for a randomsample of 100 people.

McDonalds Taco Bell Wendy's

Iron Man 20 13 7 Dispicable Me 11 9 8 Harry Potter 6 14 12

What percent of people in the sample like the movie Harry Potter?

a) 27%

b) 40%

c) 36%

d) 32%

e) 37%

Question 10

The following two-way table describes the preferences in movies and fast food restaurants for a randomsample of 100 people.

McDonald's Taco Bell Wendy's



Iron Man 20 15 5 Dispicable Me 12 7 9 Harry Potter 9 11 12

What percent of the Dispicable Me lovers also like McDonald's?

a) 43%

b) 40%

c) 9%

d) 22%

e) 21%




Question 1

Identify the population of interest in the following situation: In order to assess the membership's attitudes about a new Supreme Court decision, a local bar association

selects a SRS of 100 lawyers from its membership list. Surveys are delivered to the selected lawyers. 63 ofthe lawyers return their surveys.

a) Lawyers who returned the survey.

b) The entire membership of the local bar association.

c) The Supreme Court.

d) The 100 lawyers surveyed.

e) All lawyers.

Question 2

Define: voluntary response

a) population is divided into similar groups and a SRS is chosen from each group.

b) the explanatory variable(s) in an experiment.

c) people who choose themselves for a sample by responding to a general appeal.

d) choosing the individuals easiest to reach.

e) directly holding extraneous factors constant.

f) gives each member of the population a known chance to be selected.

g) using extraneous factors to create similar groups.

h) successively smaller groups are selected within the population in stages.

i) every possible sample of a given size has the same chance to be selected.

Question 3

Define: stratified random sample

a) population is divided into similar groups and a SRS is chosen from each group.



b) successively smaller groups are selected within the population in stages.

c) directly holding extraneous factors constant.

d) the explanatory variable(s) in an experiment.

e) every possible sample of a given size has the same chance to be selected.

f) using extraneous factors to create similar groups.

g) choosing the individuals easiest to reach.

h) people who choose themselves for a sample by responding to a general appeal.

i) gives each member of the population a known chance to be selected.

Question 4

Define: blocking

a) people who choose themselves for a sample by responding to a general appeal.

b) using extraneous factors to create similar groups.

c) the explanatory variable(s) in an experiment.

d) choosing the individuals easiest to reach.

e) gives each member of the population a known chance to be selected.

f) directly holding extraneous factors constant.

g) successively smaller groups are selected within the population in stages.

h) population is divided into similar groups and a SRS is chosen from each group.

i) every possible sample of a given size has the same chance to be selected.

Question 5

True or false: Questionnaires with non-neutral wording are likely to have response bias.

a) True

b) False

Question 6

True or false: In an experiment we impose a treatment on the subjects.



a) True

b) False

Question 7

Identify the type of sampling used in the following situation: To judge the appeal to American adults of a proposed television sitcom, a sample of 10 people from each of

three different age groups was selected and those chosen were asked to rate a pilot show.

a) Voluntary Response

b) Stratified Random Sample

c) Simple Random Sample

d) Convenience Sample

Question 8

A personnel director at a large company studied the eating habits of employees by watching the movementsof a selected group of employees at lunchtime. The purpose of the study was to determine the proportion ofemployees who buy lunch in the cafeteria, bring their own lunches, or go out to lunch.

If the director includes only the employees in the department nearest her office in her study, she isperforming a(n)

a) convenience sample

b) simple random sample

c) quota sample

d) stratified random sample


Question 9

You are going to test two new varieties of fish food vs. a commonly used fish food. You set up an experimentas follows: 60 fish are randomly assigned to each of three different tanks. One tank is randomly selected toreceive one of the new foods and another to receive the other new food. The remaining tank will receive thecommonly used food. Fish growth is measured over time. This is an example of:

a) a randomized block design.

b) a completely randomized design with no control group.

c) a completely randomized design with a control group.

d) a double blind matched pairs design.




Question 10

A game of chance is based on rolling a die two times in succession. The player wins if the larger of the twonumbers is greater than 3. Which of the following situations would simulate 8 plays of this game?

a) Choosing 48 digits from the random number table (discarding 0,7,8, and 9).

b) Choosing 2 single digits from the random number table (discarding 0,7,8, and 9).

c) Choosing 8 pairs of single digits from the random number table (discarding 0,7,8, and 9).

d) Choosing 8 digits from the random number table (discarding 0,7,8, and 9).


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PRINTABLE VERSION - UHcathy/Math2311/Lectures/may23.pdf · A real estate agent would like to predict the selling price of a single-family house by predicting the price (in thousands