The following stem-and-leaf plot represents the prices in dollars of general admission tickets for the last 26
concerts at one venue. Use the data provided to find the quartiles.
Ticket Prices in Dollars
Stem Leaves
3
0
1
1
2
5
5
6
4
0
1
2
3
5
6
7
7
5
2
2
4
4
6
3
4
5
6
6
7
9
Key: 3|0=30
Step 2 of 3 : Find the first quartile.
To find the first quartile, we need to find the value that separates the lowest 25% of the data from the rest.
There are a total of 26 data points, so the first quartile will be the 6.5th value when the data is ordered from lowest to highest.
When we arrange the data in order, we get:
30, 40, 41, 42, 45, 52, 55, 56, 57, 65, 72, 74, 75, 82, 82, 84, 86, 87, 92
The 6.5th value falls between the 6th and 7th data points, which are 52 and 55.
To find the first quartile, we take the average of the two values:
(52 + 55) / 2 = 53.5
Therefore, the first quartile is $53.50.