Estimate percentiles and individual values using a cumulative relative frequency graph.
.25 is Q1, .5 is Median, .75 is Q3. Read the x and y axis to find the corresponding information.
A cumulative relative frequency graph, or an ogive, displays the cumulative relative frequency distribution of a data set. To estimate percentiles and individual values using an ogive, follow these steps:
1. Determine the total frequency of the data set.
2. Calculate the relative frequency for each class interval by dividing the frequency for that interval by the total frequency.
3. Calculate the cumulative relative frequency for each class interval by adding the relative frequencies for all the intervals up to and including that interval.
4. Draw an ogive by plotting the upper-class limits on the x-axis and the cumulative relative frequencies on the y-axis.
5. To estimate the percentile associated with a given value, find the value on the x-axis and read the corresponding percentile on the y-axis. For example, if the value 75 falls at the 80th percentile on the cumulative relative frequency graph, we estimate that 75% of the values in the data set are less than or equal to 75.
6. To estimate an individual value associated with a given percentile, find the percentile on the y-axis and read the corresponding value on the x-axis. For example, if the 70th percentile falls at the value 90 on the cumulative relative frequency graph, we estimate that 70% of the values in the data set are less than or equal to 90.
It is important to note that these estimates are only approximations and should be interpreted with caution.
More Answers:
Master The Art Of Modeling Quantitative Data Using Density Curves: A Step-By-Step GuideHow Adding, Subtracting, Multiplying, And Dividing Constants Affect The Distribution In Mathematics
How To Calculate Standardized Scores (Z-Scores) In Data Distributions