To find the quartiles for the given dataset, we first need to sort the data (though it's already sorted) and then follow these steps:
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Find Q2 (Median):
- The dataset has 13 numbers (an odd count), so Q2 is the middle number.
- Q2 = 7th number = 127
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Find Q1:
- Q1 is the median of the first half of the dataset (the first 6 numbers).
- First half: 115, 117, 120, 122, 125, 125
- The median of these 6 numbers is the average of the 3rd (120) and 4th (122) values.
- Q1 = (120 + 122) / 2 = 121
-
Find Q3:
- Q3 is the median of the second half of the dataset (the last 6 numbers).
- Second half: 128, 131, 132, 136, 136, 140
- The median of these 6 numbers is the average of the 3rd (132) and 4th (136) values.
- Q3 = (132 + 136) / 2 = 134
Thus, the quartiles for the dataset are:
- Q1: 121
- Q2: 127
- Q3: 134
Therefore, the correct option is:
Q1: 121; Q2: 127; Q3: 134