The following histogram shows the scores on the first exam...

The following histogram shows the scores on the first exam for a statistics class.
a. How many students took the exam?
b. What is the class interval?
c. What is the class midpoint for the first class?
d. How many students earned a score of less than $70 ?$

Key Concepts

Cumulative Frequency

Cumulative frequency is a running total of frequencies through the classes in a frequency distribution. It is useful for determining the number of observations that fall below a particular value, such as when one needs to find how many data points lie beneath a given threshold.

Class Midpoint

The class midpoint is the value that lies in the center of a class interval and is calculated by taking the average of the lower and upper limits of that interval. It serves as a representative value for the data points within that interval and is especially useful in estimating the central tendency of grouped data.

Histogram

A histogram is a graphical representation of the distribution of a dataset. It displays data by grouping scores or values into bins or intervals and showing the frequency, or number of observations, that fall into each bin. This visual aid helps identify patterns such as distribution shape, central tendency, and variability.

Frequency Distribution

A frequency distribution summarizes how often different values occur within a dataset. It is commonly represented in tabular or graphical form, such as in a histogram where frequencies of data points within specified intervals are plotted, providing an overview of the data's spread and concentration.

Class Interval

A class interval is a range of values used to group data in a frequency distribution. It defines the lower and upper limits of each group in which data points are aggregated. The selection of class intervals is important because it affects how detailed or summarized the representation of the data is.

Transcript

Please give Ace some feedback