83
41
21
Third quartile
.67
If this is the only information you have, the answer would be somewhere around 125. Usually, you would find the third quartile by first finding the median. Then find the median of all of the numbers between the median and the largest number, which is the third quartile.
The Casio fx-115 ES is a scientific calculator which you can use to calculate the first and third quartiles of a data set. To calculate the first and third quartiles, you first need to arrange the data set in ascending or descending order. Once the data set is arranged, you can use the following steps to calculate the first and third quartiles: Enter the data set into the calculator by pressing the Data/Matrix button. Once the data set is entered, press the STAT button and then the VARS button. Select the data set by pressing the number key that corresponds to the data set. Access the QUARTILE option by pressing the 5 key. Enter the number 1 to calculate the first quartile or enter the number 3 to calculate the third quartile. The calculator will display the first or third quartile of the data set. These steps can be used to calculate the first and third quartiles on a Casio fx-115 ES.
The first quartile, or the lower quartile, is the value such that a quarter of the observations are smaller and three quarters are larger.The third quartile, or the upper quartile, is the value such that three quarters of the observations are smaller and a quarter are larger.
the IQR is the third quartile minus the first quartile.
Roughly speaking, finding the third quartile is similar to finding the median. First, use the median to split the data set into two equal halves. Then the third quartile is the median of the upper half. Similarly, the first quartile is the median of the lower half.
50%
75th percentile
The value of any element in the third quartile will be greater than the value of any element in the first quartile. But both quartiles will have exactly the same number of elements in them: 250.
interquartile range or IQR
83
41
21