Georgia Southwestern State University - CIS 3200Eleminary Practice Quiz-I 1)As part of a survey of college students a researcher is interested in the variable class standing

Georgia Southwestern State University - CIS 3200Eleminary

Practice Quiz-I

1)As part of a survey of college students a researcher is interested in the variable class

standing. She records a 1 if the student is a freshman, a 2 if the student is a sophomore,

a 3 if the student is a junior, and a 4 if the student is a senior. The variable class standing

is

A) categorical.

B) numerical.

C) quantitatively categorical.

D) all of the above.

2. A description of different houses on the market includes the following three variables.

Which of the variables is quantitative?

A) the square footage of the house

B) the monthly gas bill

C) the monthly electric bill

D) all of the above

3. As part of a data base on new births at a hospital some variables recorded are the age of

the mother, marital status of the mother (single, married, divorced), weight of the baby,

and gender of the baby. Of these variables

A) age, marital status, and weight are quantitative variables.

B) age and weight are categorical variables.

C) gender and marital status are categorical variables.

D) gender, marital status, and age are categorical variables.

4. When drawing a histogram it is important to

A) eliminate the extremes to minimize the effect of skewness.

B) choose class intervals so all contain a similar number of observations.

C) make certain the mean and median are contained in the same class interval, so the

correct type of skewness can be identified.

D) label the vertical axis, so the reader can determine the counts or percent in each

class interval.

Use the following to answer questions 5-6:

A poll was conducted of more than 50,000 buyers of new cars 90 days after their purchase. The data on problems per 100 vehicles for vehicles made by Toyota and General Motors are given in the time plot below for the years 1998–2004. The solid line is for General Motors and the dashed line is for Toyota.

5. In 2002 the number of problems per 100 vehicles was

A) about twice as high for General Motors as for Toyota.

B) about 20% lower for General Motors than for Toyota.

C) about 20% higher for Toyota than for General Motors.

D) about 20% higher for General Motors than for Toyota.

6. Which of the following is a true statement?

A) There quality of cars is getting poorer for both companies.

B) The number of problems was higher for General Motors than for Toyota in each

year.

C) The difference in the number of problems per 100 vehicles between General Motors

and Toyota is less than 30 for each year.

D) All of the above.

 

Use the following to answer questions 7-8:

The following histogram represents the distribution of acceptance rates (percent accepted) among 25 business schools in 2004. In each class interval, the left endpoint is included but not the right, so the class intervals are 10 ≤?rate < 15, 15 ≤?rate < 20, etc.

7. What percent of the schools have an acceptance rate below 15%?

A) 1%

B) 4%

C) 12%

D) 16%

8. The number of schools with acceptance rates over 30% is

A) 5.

B) 12.

C) 10.

D) 13.

 

Use the following to answer questions 9-10:

The bar graph below gives the distribution of the most popular colors for luxury cars made in North America in 2005.

9. Approximately what percent of luxury cars made in North America in 2005 were light

brown?

A) 5%

B) 10%

C) 15%

D) 20%

10. The total of the percents of the bars in the graph add to 90%.

A) The percent of green cars sold must be less than 4 %.

B) A pie chart could be drawn for the colors given in the bar graph.

C) The percent of luxury cars sold that are either silver or white is just over 40%.

D) None of the above.

 

Chapter 2

Practice Quiz -II

Try all the following questions. You will be given the correct answers in another file.

Use the following to answer questions 1-3:

The level of various substances in the blood is known to influence our health. Below are

measurements of the level of phosphate in the blood of a patient, in milligrams of phosphate per

deciliter of blood, made on 9 consecutive visits to a clinic.

5.6 5.2 4.6 4.9 5.7 6.4 5.9 6.7 4.2

1. What is the mean level of phosphate for the 9 clinic visits?

A) 6.15 milligrams of phosphate per deciliter

B) 5.6 milligrams of phosphate per deciliter

C) 5.47 milligrams of phosphate per deciliter

D) 4.8 milligrams of phosphate per deciliter

2. What is the median level of phosphate for the 9 clinic visits?

A) 5.6 milligrams of phosphate per deciliter

B) 5.65 milligrams of phosphate per deciliter

C) 5.7 milligrams of phosphate per deciliter

D) 6.4 milligrams of phosphate per deciliter

3. What is the first quartile for this data?

A) 4.4 milligrams of phosphate per deciliter

B) 4.6 milligrams of phosphate per deciliter

C) 4.75 milligrams of phosphate per deciliter

D) 5.6 milligrams of phosphate per deciliter

 

Use the following to answer questions 4-8:

A sample was taken of the verbal SAT scores of applicants to a California State College. The following is a boxplot of the scores.

 

4. Based on this boxplot, the interquartile range is closest to

A) 200.

B) 400.

C) 500.

D) 600.

5. Based on this boxplot, which of the following statements is true?

A) The distribution of GRE scores is fairly symmetric.

B) About half the students scored over 500.

C) Nobody scored an 800.

D) All of the above.

 

6. If each person increased his or her score by 20 points then

A) the standard deviation would increase by 20.

B) the first quartile would increase by 20.

C) the interquartile range would increase by 20.

D) None of the above.

7. About 50% of the applicants had SAT verbal scores exceeding

A) 400.

B) 500.

C) 600.

D) 700.

8. If 25 points were added to each score, then interquartile range of the new scores would

A) be increased by 5.

B) be increased by 25.

C) be increased by 625.

D) remain unchanged.

9. The five-number summary of a set of data

A) is the mean, standard deviation, first quartile, median, and third quartile.

B) is the mean, median, mode, variance, and standard deviation.

C) can be computed from the information in a stemplot.

D) is the minimum, the interquartile range, the mean, the median, and the maximum.

10. The average salary of all female workers at a large plant is $35,000. The average salary

of all male workers at the plant is $41,000. If there are more male workers than female

workers at the plant, then the average salary at the plant must be

A) exactly $38,000.

B) larger than $38,000.

C) smaller than $38,000.

D) above $41,000.

11. A consumer group surveyed the price for a certain item in five different stores and

reported the median price as $15. We visited four of the five stores and found the price

to be $10, $15, $15, and $25. Assuming that the consumer group is correct, the price of

the item at the store that we did not visit

A) must be $15.

B) must be below $15.

C) must be above $15.

D) can be any value.

 

Use the following to answer question 12:

The level of various substances in the blood is known to influence our health. Below are

measurements of the level of phosphate in the blood of a patient, in milligrams of phosphate per

deciliter of blood, made on 9 consecutive visits to a clinic.

5.6 5.2 4.6 4.9 5.7 6.4 5.9 6.7 4.2

12. What is the interquartile range for this data?

A) 1.4 milligrams of phosphate per deciliter

B) 1.7 milligrams of phosphate per deciliter

C) 1.75 milligrams of phosphate per deciliter

D) 1.9 milligrams of phosphate per deciliter

 

Chapter 3

Practice Quiz for Chapter 3

Try all the problems. The correct answers are given in another file.

Use the following to answer questions 1-2:

1. For this density curve, what percent of the observations lie below 0.7?

A) 25%

B) 35%

C) 40%

D) 70%

2. For this density curve, what percent of the observations lie between 0.50 and 1.5?

A) 0.25%

B) 12.5%

C) 25%

D) 50%

Use the following to answer questions 3-5:

The scores on the Wechsler Adult Intelligence Scale are approximately Normal with μ = 100 and

σ = 15.

3. The proportion of adults with scores between 90 and 110 is closest to

A) 0.250.

B) 0.432.

C) 0.500.

D) 0.667.

4. The proportion of adults with scores above 130 is closest to

A) 0.001.

B) 0.025.

C) 0.050.

D) 0.950.

5. How high a score is needed to be in the highest 5%?

A) 115.

B) 124.

C) 130.

D) 135.

6. A Normal density curve has which of the following properties?

A) It is symmetric.

B) It has a peak centered above its mean.

C) The spread of the curve is proportional to the standard deviation.

D) All of the above.

7. Using the standard Normal distribution tables, the area under the standard Normal curve

corresponding to Z > –1.62 is

A) 0.0044.

B) 0.0526.

C) 0.9474.

D) 0.9956.

8. Using the standard Normal distribution tables, what is the area under the standard

Normal curve corresponding to Z < 0.75?

A) 0.0401

B) 0.7500

C) 0.7734

D) 0.9599

9. Using the standard normal distribution tables, the area under the standard Normal curve

corresponding to –0.5 < Z < 1.2 is

A) 0.3085.

B) 0.8849.

C) 0.5764.

D) 0.2815.

Use the following to answer questions 10-11:

Birthweights at a local hospital have a Normal distribution with a mean of 110 oz and a standard

deviation of 15 oz.

10. The proportion of infants with birthweights above 125 oz is

A) 0.500.

B) 0.159.

C) 0.341.

D) 0.841.

11. The proportion of infants with birthweights between 125 oz and 140 oz is

A) 0.819.

B) 0.636.

C) 0.477.

D) 0.136.

Use the following to answer questions 12-14:

A market research company employs a large number of typists to enter data into a computer

database. The time taken for new typists to learn the computer system is known to have a Normal

distribution with a mean of 130 minutes and a standard deviation of 20 minutes. A candidate is

automatically hired if he or she learns the computer system in less than 100 minutes. A cut-off

time is set at the slowest 40% of the learning distribution. Anyone slower than this cut-off time is

not hired.

12. The proportion of new typists that take under two hours to learn the computer system is

A) 0.023.

B) 0.067.

C) 0.159.

D) 0.309

13. What proportion of candidates will be automatically hired?

A) 0.023

B) 0.067

C) 0.159

D) 0.309

Page 3

14. What is the cut-off time the market research company uses?

A) 2 hours and 8 minutes

B) 2 hours and 14 minutes

C) 2 hours and 30 minutes

D) 2 hours and 40 minutes

Use the following to answer question 15:

15. For this density curve, the first quartile is

A) 0.5.

B) 0.75.

C) 1.5.

D) 1.75.

 

Chapter 4

Name: __________________________ Date: _____________

1. The Columbus Zoo conducts a study to determine whether a household's income can be used to predict the amount of money the household will give to the zoo's annual fund

drive. The response variable in this study is

A) the Columbus Zoo.

B) a household's income.

C) the amount of money a household gives to the zoo's annual fund drive.

D) all households in Columbus.

2. Does exposure to classical music (through instrument lessons or concert attendance)

improve children's scholastic performance? In a study, researchers measured the amount of exposure to classical music for many children, along with their scores on the state's academic proficiency exam. The explanatory variable in this study is

A) the type of instrument a child plays.

B) the child's score on the state's proficiency exam.

C) the amount of a child's exposure to classical music.

D) whether a child passed the state's proficiency exam.

 

Use the following to answer questions 3-4:

The volume of oxygen consumed (in liters per minute) while a person is at rest and while he or she is exercising (running on a treadmill) was measured for each of 50 subjects.The goal is to determine if the volume of oxygen consumed during aerobic exercise can be estimated from the amount consumed at rest. The results are plotted below.

3. In this study, the response variable is

A) the volume of oxygen consumed at rest.

B) the volume of oxygen consumed while running.

C) It doesn't matter which is considered the response. Either variable is appropriate.

D) the measuring instrument used to measure the volume of oxygen consumed.

4. The scatterplot suggests

A) there is a positive association between the volume of oxygen consumed at rest and

while running.

B) there is an outlier in the plot.

C) both a and b.

D) neither a nor b.

 

5. Do creative people make better salespeople? Ten sales staff in a large company were given a creativity test (scores range from 0 to 20, with higher scores indicating greater creativity) and were evaluated regarding sales growth performance (a score of 100 indicates an average performance, and larger scores indicate better performance). The creativity scores and sales growth performance scores are given below. We want to investigate if creative people tend to perform better with regard to sales growth. Which of the following is a proper scatterplot of these data given the goals of the study?

A)

B)

 

 

C)

 

D)

6. Consider the following scatterplot.

The form of the relationship represented in the plot is best described as

 

A) strongly curved.

B) negative association.

C) clusters.

D) all of the above.

 

7. A researcher measures the correlation between two variables. This correlation tells us

A) whether there is a relation between two variables.

B) whether a scatterplot shows an interesting pattern.

C) whether a cause and effect relation exists between two variables.

D) the strength and direction of a straight line relation between two variables.

Use the following to answer questions 8-9:

We want to determine the correlation between the height (in inches) and scoring average (points per game) of women on a college basketball team. To do this, we record the height and scoring average of two players on the team. The values are Player #1 Player #2 Height 70 75 Scoring average 11.0 20.0

8. The correlation r computed from the measurements on these players is

A) 1.0.

B) positive and between 0.25 and 0.75.

C) near 0, but could be either positive or negative.

D) exactly 0.

9. The correlation r would have units in

A) inches.

B) points.

C) inches-points.

D) no units. Correlation is a unitless quantity.

 

Use the following to answer questions 10-11:

Refer to the following scatterplot For each menu item at a fast food restaurant, fat content (in grams) and number of calories were recorded. A scatterplot of these data is given:

10. A plausible value for the correlation between weight and mpg is

A) +0.2.

B) – 0.9.

C) +0.9.

D) – 1.0.

11. Suppose we changed the units of fat from grams to ounces. Which of the following

statements is correct?

A) The new scatterplot would look a bit different, and the new correlation would be

smaller.

B) The new scatterplot would look a bit different, but the correlation would be

unchanged.

C) The new scatterplot would be unchanged, and so would the correlation.

D) The new scatterplot would be unchanged, but the new correlation will be smaller.

12. Which of the following is not true of the correlation coefficient r?

A) Multiplying all data values (x's and y's) by 10 will have no impact on r.

B) If r = 0, then there is no relationship between x and y.

C) If r is the correlation between x and y, then r is also the correlation between y and x.

D) –1 ≤?r ≤?1.

 

13. Consider the following scatterplot of the horsepower of several models of cars vs. gas mileage (mpg).

The correlation between x and y

A) is approximately 0.8.

B) is approximately – 0.7.

C) is approximately 0.0.

D) cannot be computed because the trend is curved.

 

Chapter 5

Practice Quiz- Chapter 5

Use the following to answer question 1:

In a study, fast-food menu items were analyzed for their fat content (measured in grams) and calorie content. The goal is to predict the number of calories in a menu item from knowing its fat content. The least-squares regression line was computed, and added to a scatterplot of the these data:

 The equation of the least-squares regression line is:

Calories = 204 + 11.4 x (Fat)

The correlation between Calories and Fat is r = .979. Hence, r2 = .958. Finally, the average number of calories in menu items is 663, and the average fat content in menu items is 40 grams.

1. Which of the following is true?

A) The least-squares regression line passes through the point (40,663).

B) 95.8% of the data points fall on the least-squares regression line.

C) The data point denoted by *is highly influential.

D) All of the above.

 

2. A researcher wants to determine whether the rate of water flow (in liters per second)

over an experimental soil bed can be used to predict the amount of soil washed away (in kilograms). The researcher measures the amount of soil washed away for various flow rates, and from these data calculates the least-squares regression line to be

amount of eroded soil = 0.4 + 1.3 × (flow rate) The correlation between amount of eroded soil and flow rate would be

A) 1/1.3.

B) 1.3.

C) positive, but we cannot say what the exact value is.

D) either positive or negative. It is impossible to say anything about the correlation

from the information given.

Use the following to answer questions 3-4:

The following is a scatterplot for profits versus sales (in tens of thousands of dollars) of 12 companies selected randomly from the year 1986 Forbes 500 list of companies. The correlation between Sales and Profits is 0.934.

3. From this information we see

A) profits can be accurately predicted from sales.

B) there is a clear error since profits cannot be negative.

C) there is a very influential observation in the data.

D) all of the above.

 

4. If we omitted the observation in the far upper-right corner of the scatterplot, the

correlation would

A) decrease.

B) increase.

C) change very little.

D) there isn't enough information to say.

5. A study of elementary school children, aged 6 to 11, finds a high positive correlation

between shoe size x and score y on a test of reading comprehension. The observed

correlation is most likely due to

A) the effect of a lurking variable, such as age.

B) a mistake, since the correlation must be negative.

C) cause and effect (larger shoe size causes higher reading comprehension).

D) “reverse” cause and effect (higher reading comprehension causes larger shoe size).

6. Which of the following would be necessary to establish a cause-and-effect relation

between two variables?

A) There is a strong association between the variables.

B) An association between the variables is observed in many different settings.

C) The alleged cause is plausible.

D) All of the above.

7. A researcher obtained the average SAT scores of all students in each of the 50 states, and the average teacher salaries in each of the 50 states. She found a negative correlation between these variables. The researcher concluded that a lurking variable must be present. By lurking variable she means

A) a variable that is not among the variables studied but which affects the response

variable.

B) the true cause of a response.

C) any variable that produces a large residual.

D) the true variable, which is explained by the explanatory variable.

 

Use the following to answer questions 8-12:

In a study, fast-food menu items were analyzed for their fat content (measured in grams) and calorie content. The goal is to predict the number of calories in a menu item from knowing its fat content. The least-squares regression line was computed, and added to a scatterplot of the these data:

The equation of the least-squares regression line is:

Calories = 204 + 11.4 x (Fat)

The correlation between Calories and Fat is r = .979. Hence, r2 = .958. Finally, the average number of calories in menu items is 663, and the average fat content in menu items is 40 grams.

8. We might feel comfortable using the least-squares regression equation to predict calories for a menu item having fat content

A) roughly between 0 and 500 grams.

B) roughly between 0 and 120 grams.

C) more than 120 grams.

D) cannot be determined from the information provided.

9. The least-squares line would predict that a menu item with 40 grams of fat would have

A) 100 calories.

B) 204 calories.

C) 660 calories.

D) 456 calories.

 

10. The point indicated by * has

A) a negative value for the residual.

B) a positive value for the residual.

C) a zero value for the residual.

D) a zero value for the correlation.

11. A menu item's fat content is

A) the intercept.

B) the slope.

C) the explanatory variable.

D) the response variable.

12. Which of the following statements is true?

A) About 95.8% of the variation in calories for menu items is explained by the

regression on Fat content.

B) According to the least-squares regression line, the number of calories in a non-fat

menu item (Fat = 0) is predicted to be 204.

C) According to the least-squares regression line, we would predict an increase of 11.4

calories if we add one gram of fat to a menu item.

D) All of the above.