When drawing a histogram, it is important to
a. eliminate the extremes to minimize the effect of skewness.
b. choose class intervals, so they all have the same number of observations
c. make sure that the mean and the median fall in the same class interval, so that the correct type of skewness can be identified.
d. label the vertical axis, so the reader can determine the counts or percent in each class interval.
When drawing a histogram, it is important to:
d. label the vertical axis, so the reader can determine the counts or percent in each class interval.
To create a histogram, you should follow these steps:
1. Choose the appropriate number of class intervals: Selecting the number of class intervals is crucial, as too few or too many intervals may result in an inaccurate representation of the data. Generally, it is recommended to use between 5 and 15 intervals, depending on the data set size.
2. Determine the width of each class interval: To calculate the width, subtract the minimum value from the maximum value of your data set and divide it by the number of class intervals. Ensure the intervals are equal in size.
3. Create the horizontal axis: Place the class intervals on the horizontal axis, with each interval represented by a bar on the graph.
4. Determine the frequency/count of data points falling within each interval: Count the number of data points that fall into each interval and plot the corresponding count on the vertical axis. This axis represents the frequency of data points in each interval.
5. Draw the bars: Draw vertical bars above each class interval on the horizontal axis. The height of each bar corresponds to the frequency (or counts) of data points in that interval.
6. Label the vertical axis: It is crucial to label the vertical axis to provide the reader with information about the counts or percentage of observations in each class interval. This labeling allows for easier interpretation of the data.
Regarding the other options:
a. Eliminating the extremes to minimize the effect of skewness is not necessary for creating a histogram. Skewness is a property of the data distribution, and removing extremes would alter the distribution.
b. Choosing class intervals with an equal number of observations is not a requirement for drawing a histogram. While it can be helpful in certain cases, it is not universally necessary.
c. Ensuring that the mean and median fall in the same class interval is not a fundamental requirement for constructing a histogram. The shape and skewness of a distribution can be determined by other methods, such as examining the shape of the bars or using statistical measures like skewness.