Math 125 Exam 1

A histogram is a graph that represents the cumulative frequencies for the classes in a frequency distribution.

False

Based on her electric bills from last year, Mrs. Smith expects she will be paying $75/month this year. This is an example of descriptive statistics.

False

If a distribution is negatively skewed as shown in the figure below, the mean will fall to the right of the median and the mode will fall to the left of the median.

False

In a research study, it is always preferable for the researcher to carefully choose his participants rather than randomly select them from a suitable group..

False

The coefficient of variation for a data set is the mean divided by the standard deviation, expressed as a percentage.

False

Which graph should be used to represent the frequencies with which certain courses are taken at Highlands Middle School?

Pareto chart

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

The confounding variable influences the dependent variable, but is not separated from the independent variable.

Indicate which student has the higher z score. Art Major X=46 X=50.5 s=5.2 Theater Major X=70 X=75.1 s=7.3

The theater major has a higher score than the art major.

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

True

The percentile corresponding to a given data value X is computed by adding the 0.5 to number of values less than X then dividing by the total number of values in the data set.

True

According to Chebyshev's theorem, the maximum proportion of data values from a data set that are more than 2.5 standard deviations from the mean is _________.

0.16

For the class 5 - 17, the upper class limit is

17

The grades for the trigonometry exam are listed below. Find the range. 85, 76, 93, 82, 84, 90, 75

18

Determine the range for the following data set. 4, 7, 3, 16, 5, 22, 8

19

If a set of data has 64 values with a variance of 16.8, then the standard deviation is _________.

4.1

Find the class with the least number of data values.

85-95

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

9

Greg wants to construct a frequency distribution for the political affiliation of the employees at Owen's Hardware Store. What type of distribution would be best?

categorical

Statistics is the science of conducting studies to

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

If a researcher manipulates one of the variables and tries to determine how the manipulation influences other variables, the researcher is conducting a(n)

experimental study

An independent variable can also be called a(n)

explanatory variable.

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

inferential statistics

The size of the box in a boxplot shows the ____________________ of the data set.

interquartile range

If a weather center monitors and calculates the average number of tornadoes that pass through Topeka, Kansas each year, what type of variable would they be investigating?

random variable