Math-exam 1

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

-3

Find the class boundaries for class 15-25.

14.5-25.5

If two classes are 10-16 and 17-23, then the upper class boundary of 10-16 is

16.5

Using the class 23-35, what is the upper class boundary

35.5

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

5

What is the median of the following numbers? 2, 4, 7, 9, 13

7

What is the midpoint of the class 6-10?

8

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

9

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

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

______ are used to represent a frequency distribution for a categorical variable, and the frequencies are displayed by the heights of vertical bars, which are arranged in order from highest to lowest.

Pareto charts

Which is NOT true ?

The sum of three relative frequencies will not always be 1.

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

categorical frequency distribution

The ______ is obtained by first adding the lower and upper limits and then dividing by 2.

class midpoint

Statistics is the science of conducting studies to

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

Statistics os the science of conducting studies to ______

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

A ______ variable assumes values that can be counted

discrete

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

false

The three most commonly used graphs in research are the histogram, the ______, and the cumulative frequency graph (ogive).

frequency polygon

The ______ variable in an experimental study is the one that is being manipulated by the researcher.

independent

Based on a random sample of 1000 people, a researcher obtained the following estimates the percentage of people lacking health insurance in one U.S. city.

inferential

The average age of students at a local college is 20.5 years

mean

One half of the factory workers make more than $7.89 per hour, and one half makes less that $7.89 per hour

median

There is an extreme value in the data set

median- it is affected less than the mean by extremely high or low values

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

misleading graph

Most people prefer red convertibles over any other color

mode

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

nominal

The ______ level of measurement exhausts categories in which no order or ranking can be imposed on the data.

nominal

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

nominal

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

pie

A ______ consists of all subjects (human or otherwise) that are being studied.

population

Variables with values that are determined by chance are called ______

random variables

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

ratio

100,000 randomly selected adults were asked whether they drink at least 48 oz of water each day and only 45% said yes. Identify the sample and population.

sample: the 100,000 selected adults; population: all adults

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

sampling

A stem and leaf plot is useful for

showing the distribution of costs of textbooks for various courses

If data is clustered at one end or the other, it indicates that there us a ______.

skewed distribution

The ______ retains the actual data while showing them in graphical form.

stem and leaf plot

Researchers obtain _____ samples by dividing the population into groups according to some characteristics that is important to the study, then sampling from each group.

stratified

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

the class limits are difficult to interpret

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

the trend of the data over time

A frequency polygon and a histogram have the same overall shape.

true

A pie graph was created showing the number of children per family. If 234 families were in the survey and the section depicting families with three children represented 120 degrees, the number of families with three children was 78.

true

An ogive is also called a cumulative frequency graph

true

When two sets of data are compared on the same graph using two lines, it is called a compound time series graph.

true

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

use a class width with an even number

Ambiguous averages contain all of the following EXCEPT the

variance