Stats Exam 1

Which of the following statements are true of histograms?

- A histogram is a graph suited to displaying quantitative values -The classes are marked along the horizontal axis of the histogram graph -Histograms provide a visual representation of the distribution -The area of each bar should be proportional to the relative frequency of the class it represents

Which of the following statements apply to class midpoints?

-A class midpoint is the halfway point between the lower limit and the upper limit of the class -A class midpoint is the average of the values that define the class interval -A class midpoint can be found by adding the lower limit and the upper limit of the class together and dividing the two.

Which of the following features are par of a histogram?

-The frequency of occurrence of data -Quantitative data divided into classes -adjacent bars whose weight represents a number or fraction

Which of the following statements describe class boundaries?

-for each class, the value of lower boundary for a class is a part of the class, but the upper boundary is not. -There is a lower boundary and an upper boundary for each class. -For every consecutive pair of classes, the upper boundary of the prior class is the same value as the lower boundary for the next class.

Raw Data

Before data are organized into classes to make a frequency distribution, they are referred to as

Which statement best explains a frequency table?

Data grouped into classes showing the number of observations in each class

Calculate an appropriate Class Width given a set of Raw Data

Example of Class Width in photo.

Form Classes from a Set of Raw Data

Example of Form classes from raw data

Form Class Boundaries from a given set of classes

Example of forming class boundaries from given set of classes

True or false: Class boundaries are numerical values that seperate or define classes without the gaps that usually exist between class limits

True Class boundaries define the classes in a way that allows each class to share a boundary with at least one other class

Frequency distribution

distribution groups data into intervals called classes and records the number of observations that falls into each class.

Relative frequencies

indicate the proportion of subjects that fell into each class. They make it possible to compare the results in different studies the same topic even when they use different sample sizes.

In a frequency table, the numerical entry in the relative frequency column for each class represents

the fraction of observations in that class.