To calculate the quartiles (Q1, Q2, and Q3) for the dataset:
Dataset: 115, 117, 120, 122, 125, 125, 127, 128, 131, 132, 136, 136, 140
Step 1: Sort the data (already sorted) The data is already sorted in ascending order.
Step 2: Calculate Q2 (Median) The median (Q2) is found by taking the middle number of the dataset. Since there are 13 numbers (odd count), the median is the 7th number:
Q2 = 127 (the middle number)
Step 3: Calculate Q1 (First Quartile) Q1 is the median of the first half of the dataset (the first 6 numbers):
First half: 115, 117, 120, 122, 125, 125
Median of first half (Q1) = (120 + 122) / 2 = 121
Step 4: Calculate Q3 (Third Quartile) Q3 is the median of the second half of the dataset (the last 6 numbers):
Second half: 128, 131, 132, 136, 136, 140
Median of second half (Q3) = (132 + 136) / 2 = 134
Therefore, the quartiles are:
- Q1 = 121
- Q2 = 127
- Q3 = 134
The correct response is: Q1: 121; Q2: 127; Q3: 134