Statistics Midterm Ch.1-3

True

A time series graph is useful for detecting trends that occur over the period of time.

True

A time series graph represents data that occur over a specific time period.

time series graph

A weatherman records the amount of rain that fell in Portland, Oregon each day for a year. What type of graph should he use to show how rainfall changes during the year ?

The average age of teachers at a local college is 42 with a standard deviation of 7.3. The average age of high school teachers is 38 with a standard deviation of 12. Which group is more variable?

Ages of high school teachers.

What is included in measures of central tendency?

All of the above

detached statistics

An advertisement for a lawn mower states that it is 10% more powerful than it's competitor. This is an example of

80 degrees

An automobile dealer wants to construct a pie graph to represent types of cars sold in July. He sold 72 cars; 16 of which were convertibles. The convertibles will represent how many degrees in the circle?

explanatory variable.

An independent variable can also be called a(n)

True

An ogive is also called a cumulative frequency graph.

Positive relationship

Analyze the scatter plot. https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/HW2_4_10115131400/f1q4g1.jpg

END OF CHAPTER 1

BEGINNING OF CHAPTER 2

There is no relationship.

Daniel Wiseman, a scientist for Gres-Trans Corp., wants to determine if the flow rate of a particular material changes with different changes in temperature. The data is plotted in the figure below. What type of relationship exists between the flow rate and the change in temperature? https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00016731d6531914c/f2q76-1.png

positive

Determine the type of relationship shown in the figure below. https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00016731d6531914c/f2q75-1.png

misleading graph

Exaggerating a one-dimensional increase by showing it in two dimensions is an example of a(n)

A five-number summary of a data set consists of the minimum, Q1, the mean, Q2, and the maximum.

False

The interquartile range or IQR is found by subtracting the mean from the maximum value of a data set.

False

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00016731d6531914c/f2q22-1.jpg : (55-65)

Find the class with the greatest number of data values.

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00021adcee012317d/q23-1.png : (60)

Find the class with the greatest number of data values.

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00016731d6531914c/f2q21-1.jpg : (85-95)

Find the class with the least number of data values.

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00021adcee012317d/q22-1.png : (90)

Find the class with the least number of data values.

False

For a given data set, the ogive and the frequency polygon will have the same overall shape.

a discrete variable

If a variable has only the possible values 1, 3, and 16, then this variable is

True

If every 13th customer leaving a movie were surveyed, this would be an example of systematic sampling.

right-skewed

If the graph of a frequency distribution has a peak and the data tapers off more slowly to the right and more quickly to the left, the distribution is said to be ____________.

True

If the limits for a class were 20-38, the boundaries would be 19.5-38.5.

nominal

If you classified the fruit in a basket as apple, orange, or banana, this would be an example of which level of measurement?

sampling

If you were told that four students from a class of twenty were questioned for a grade versus test preparation poll, this would be an example of

negative linear

In a __________ relationship, as one variable increases, the other variable decreases, and vice versa.

120 degrees

In a pie graph, if pepperoni pizza were 24/72 of the distribution, how many degrees would be needed to represent pepperoni?

quasi-experimental study

In a true experimental study, the subjects should be assigned to groups randomly. If this is not possible and a researcher uses intact groups, they are performing a

True

Inferential statistics is based on probability theory.

Find the mean, mode, median, and midrange value for the following data set. 12, 15, 18, 18, 15, 22, 15, 30, 12

Mean: 17.4 Mode: 15 Median: 15 Midrange: 21

The ______________ is the midpoint in a data array.

Median

Solve. If necessary, round answers to the nearest hundredth. The following test scores were recorded for a student: 83, 78, 76, 72, 78, 64, 74. Find the median.

Median:76

The _________ is defined as the sum of the lowest and highest values in the data set, divided by 2.

Midrange

A ____________relationship exists when the points fall approximately in a DESCENDING straight line from left to right.

Negative linear

Analyze the scatter plot. https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/HW2_4_10115131400/f1q5g1.jpg

Negative relationship

A _________ relationship exists when the points are scattered everywhere in the graph.

None of the above

Find the mode. 54 55 56 57 58 59 60

None of the above

What is the term for a characteristic or measure obtained by using all the data values for a specific population?

Parameter

all of the above

Probability differs from statistics in that

The following set of date values has the same average. Which set is more variable? a. {5,5,5,11,17,17,17} b. {5, 6, 7, 11, 15, 16, 17}

Set a is more variable than b

frequency

The __________ is the number of values in a specific class of distribution.

ordinal

The _______________ level of measurement classifies data into categories that can be ranked; however, precise differences between the ranks do not exist.

Reasonably symmetric

The data shown in the following stem and leaf plot https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00021adcee012317d/q80-1.png

Given the following boxplot where m is the median value, what statement could be made about the distribution of the data? https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg000326ffee012317e/q67-1.png

The distribution is approximately symmetric. https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg000326ffee012317e/q67-2.png

Describe the possible nature of the distribution https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/ESQ3_120212130751/f1q4g1.jpg

The distribution is somewhat negatively skewed

relative frequency graphs

The graphs that have their distributions as proportions instead of raw data as frequencies are called

False

The number of birds in a tree is an example of a continuous variable.

ratio

The number of people from the state of Alaska who voted for a Republican in the last election is an example of the ______________ level of measurement.

pie

The percentage of white, wheat, and rye bread sold at a supermarket each week is best shown using a __________ graph.

scatter plot

The possible relationship between pairs of data values could be examined from a

the class limits are difficult to interpret

The range 33.17 - 35.63 is not a good choice for class boundaries because

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00021adcee012317d/q38-1.png : (20)

The total frequency of the data whose histogram is shown below

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00021adcee012317d/q32-1.png : (34)

The total frequency of the data whose ogive shown below

Independent variable and dependent variable

The two variables in a scatter plot are called the

Categorical frequency distribution

Thirty students recorded the colors of their eyes, choosing from the colors brown, blue, green, hazel, and black. This data can be appropriately summarized in a

A weighted mean is used when the values of the data set are not all equally represented.

True

Methods commonly called traditional statistics include using measures of position, Chebyshev's theorem, and the coefficient of variation.

True

The median can be a more appropriate measure of central tendency if the distribution of the data is extremely skewed.

True

The percentile rank corresponding to a given value X is computed by adding the 0.5 to number of values below X and dividing this value by the total number of values within the data set and then multiplying the result by 100.

True

random variables

Variables with values that are determined by chance are called

The ______________ is the average of the squares of the distance each value is from the mean.

Variance

The _______________and ______________ are used to determine the consistency of a variable.

Variance and standard deviation

10.5 and 17.5

What are the boundaries of the class 11-17?

3 and 19

What are the limits of the class 3-19?

13

What is the lower class limit in the class 13-17?

9

What is the lower class limit in the class 9-13 ?

11

What is the midpoint of the class 4-18?

8

What is the midpoint of the class 6-10 ?

variable

What is the term for a characteristic or attribute that can assume different values?

The average price of an electric tooth-brush is $5.25 with a standard deviation of $1.25. Using Chebyshev's theorem, find the price range for which at least 55.56% of the tooth-brushes will sell.

$3.38 to $7.13

The mean of {-4, -2, -2, -2, -4, 2} is

-2

What is the median of the following numbers? -13, 1, -1, -5, -1, -6, -5, -1

-3

The minimum of the set of numbers {-1, 19, -5, 11, 5} is

-5

A student scored 84 points on a test where the mean score was 82 and the standard deviation was 5. The student's z score was

.40

How many outliers are present in the following list of data values? {3 ,5, 17, 26, 32} Use the following code to answer the question: 0=none, 1=one, 2=two,

0

The median of {-2, 0, 0, 0, -2, 4} is

0

According to Chebyshev's theorem, the proportion of values from a data set that is further than 1.5 standard deviations from the mean is:

0.22

A student scored 84 points on a test where the mean score was 82 and the standard deviation was 5. The student's z score was

0.40

According to Chebyshev's theorem, the proportion of values from a data set that is within 2.5 standard deviations is at least:

0.84

Given that the variance for a data set is 1.20, what would be the standard deviation?

1.10

What is the z score for a batter who normally averages 0.325, with a standard deviation of 0.065 if he scores 0.410 for one game?

1.308

Find the Interquartile rage (IQR) for the following data set: 5, 6, 12, 13, 15, 18, 22, 50

11

An industrial worker reported the number of new pipelines the company acquired per day for a given week: 12 14 12 2 15 17 11 Find Q1, the median and Q3, respectively.

11, 12, 15

Given that the mean of a set of data is 25 and the standard deviation is 3, what would be the coefficient of variation?

12%

What is the midrange of the following numbers? 7, 13, 12, 14, 6, 14, 20, 20, 20

13

The range of the set of numbers {8, 17, 3, 10, 5} is

14

Determine the range for this data: 7, 15, 11, 9, 23

16

Find the mean, mode, median, and midrange value for the following data set. 12, 15, 18, 18, 15, 22, 15, 30, 12

17.4; 15; 15; 21

What is the range of the numbers -6, 1, -8, 2, 10

18

Determine the range for this data: 4, 7, 3, 16, 5, 22, and 8.

19

The maximum of the set of numbers {5, 19, -5, 11, 5} is

19

Find the variance and standard deviation given the following group frequency distribution: class limits frequency 1-3 6 4-6 8 7-9 10 10-12 7 13-15 0 16-18 5

21.6; 4.6

In a statistics course the average final exam score is 55 with a standard deviation of 1.5. Find the z-score for a test score of 88.

22

For the table below, calculate the cumulative percent of the students that fell within the B class. Grade Class Boundaries Frequency A 89.5-99.5 4 B 79.5-89.5 7 C 69.5-79.5 11 D 59.5-69.5 3 F 49.5-59.5 3

39%

The cost in dollars of manufacturing x motorized scooters is given by a. Complete the following table and graph the results. Motorized Scooter Costs https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/ESQ2_20129130929/f1q1g3.jpg

47,000

Find the median for the following data. 6, 7, 4, 5, 3, 7, 4

5

Which of the following is the mode for the given data? 5, 4, 3, 4, 5, 6, 5, 5, 3, 4

5

Given the following data set, find the value that corresponds to the 75th percentile. 10, 44, 15, 23, 14, 18, 72, 56

50

If a set of 25 numbers has standard deviation 8, then it's variance is

64.00

Solve. If necessary, round answers to the nearest hundredth. The following test scores were recorded for a student: 72, 64, 60, 60, 72, 74. Find the midrange.

67

Find the mean. If necessary, round to one decimal place. 15, 4, 7, 16, 6, 13, 1, 10

9

The mean of {5, 12, 10, 8, 10} is

9

Find the mode or modes (if any). 95, 25, 95, 13, 25, 29, 56, 95

95

The mean of a distribution is 18 with a standard deviation of 3. Approximately what percent of the values will fall between 12 and 24?(Use the Empirical (Normal) Rule)

95%

In a statistics course the average final exam score is 84 with a standard deviation of 5. Find the test score that corresponds to a z-score of 2.3.

95.5

The categories are listed alphabetically

A Pareto chart does not have which of the following properties?

quantitative variable on the horizontal axis

A Pareto chart does not have which of the following properties?

none of the above

A _________ relationship exists when the points are scattered everywhere in the graph.

time series graph

A __________ graph would most appropriately represent the number of students that were enrolled in Statistics for each of the past ten years.

discrete

A ______________ variable assumes values that can be counted

False

A grouped frequency distribution is used when the range of the data values is relatively small.

88

A linear regression line y = 10 + 0.9x is computed to predict the final exam score y on the basis of the first score x on the first test. Suppose Maria scores a 87 on the first test. What would be the predicted value of her score on the final exam?

changing the subject

A magazine tests a new car and reports that it could be twice as fun to drive as it's predecessor. This is NOT an example of

The trend of the data over time

A pie graph is not useful to show which of the following characteristics of data?

False

A pie graph would best represent the number of inches of rain that has fallen in Ohio each day for the past 2 months.

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00016731d6531914c/f2q72-18.png

A recent statistics exam yielded the following 10 scores. Construct a frequency polygon distribution using the class limits shown below. 80, 99, 77, 67, 93, 71, 76, 86, 79, 71

A positive linear relationship

What kind of relationship does the scatter plot show between x and y? https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00021adcee012317d/q83-1.png

No linear relationship

What kind of relationship does the scatter plot show between x and y? https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00021adcee012317d/q84-1.png

This is not a scatter plot

What kind of relationship does the scatter plot show between x and y? https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00021adcee012317d/q86-1.png

nominal

What level of measurement classifies data into mutually exclusive (nonoverlapping), exhaustive categories in which no order or ranking can be imposed on the data?

Pareto chart

What type of graph is the figure below?

stratified sampling

What type of sampling is being employed if the country is divided into economic classes and a sample is chosen from each class to be surveyed?

grouped

When the range is large, and classes that are several units in width are needed, a __________ frequency distribution is used.

inferential statistics

Which branch of statistics would employ probability to predict how many miles one would be able to drive a 2000 Toyota Celica during its lifetime?

The confounding variable influences the dependent variable, but cannot be separated from the independent variable.

Which of the following best defines the relationship between confounding, dependent, and independent variables?

A sample is a group of subjects selected from a population to be studied

Which of the following correctly describes the relationship between a sample and a population?

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00016731d6531914c/f2q25-2.png

Which of the following could be a cumulative frequency graph?

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00021adcee012317d/q81-2.png

Which of the following graphs is the scatter plot for the data given below? x values 9 9 12 5 1 y values 4 2 9 6 6

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00021adcee012317d/q63-1.png

Which of the following is a Pareto chart?

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00016731d6531914c/f2q34-3.png

Which of the following is a frequency polygon?

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg00016731d6531914c/f2q27-4.jpg

Which of the following is a histogram?

use a class width with an even number

Which of the following should not be done when constructing a frequency distribution?

histogram

Which type of graph represents the data by using vertical bars of various heights to indicate frequencies?

hypothesis testing

______________ is a decision-making process for evaluating claims about a population, based on information obtained from samples.

The given percentile graph was constructed using a sample of 50 cholesterol readings. Let X represent a persons cholesterol readings and let Y represent the cumulative percentages. https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/ESQ3_90212130857/f1q5g1.jpg If a persons has a cholesterol reading of 118 then he/she would be at the following percentile:

approximately 82nd

Statistics is the science of conducting studies to

collect, organize, summarize, analyze, and draw conclusions from data.

A school secretary reported the number of absences of 3rd grade students in 2 weeks: 12 13 9 17 16 2 8 14 7 5 13 18 3 4 Construct a boxplot for the data.

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/HW3_40212130935/f1q3g1.jpg

Q1, Q2, and Q3 for the following data set. 7, 21, 32, 38.

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg000326ffee012317e/q66-4.png

Find Q1, Q2, and Q3 for the following data set. 7, 21, 32, 38.

https://mycourses.utrgv.edu/courses/1/56533.201720/ppg/d6/brg000326ffee012317e/q66-6.png

Check the following data set for any outliers 121, 125, 130, 127, 123, 130, 122, 121

none

If the boxplot for one set of data is much wider than the boxplot for a second set of data, then

none of the above need to be true

The average age of instructors at a local college is 55, with a standard deviation of 6 years; the average salary is $37,000 with a standard deviation of $4100. Which is more variable?

salary

Use the range rule of thumb to estimate the standard deviation of the following sample 12, 18, 9, 9, 11, 14

s≈2.25

If the five number summary for a set of data is 0, 3, 6, 7, and 16, then the mean of this set of data is

there is insufficient information to calculate the mean