To calculate the quartiles for the given dataset, we first need to sort the dataset (though it is already sorted in this case):
The dataset: 115, 117, 120, 122, 125, 125, 127, 128, 131, 132, 136, 136, 140
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Finding Q2 (Median):
- The number of data points (n) is 13, which is odd.
- Q2 (the median) is the middle value:
- Median = 7th value = 127.
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Finding Q1:
- Q1 is the median of the first half of the data (the lower 6 values):
- Lower half: 115, 117, 120, 122, 125, 125
- Q1 = Median of (115, 117, 120, 122, 125, 125) = (120 + 122) / 2 = 121.
- Q1 is the median of the first half of the data (the lower 6 values):
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Finding Q3:
- Q3 is the median of the second half of the data (the upper 6 values):
- Upper half: 128, 131, 132, 136, 136, 140
- Q3 = Median of (128, 131, 132, 136, 136, 140) = (132 + 136) / 2 = 134.
- Q3 is the median of the second half of the data (the upper 6 values):
Therefore, the quartiles for the dataset are:
- Q1 = 121
- Q2 = 127
- Q3 = 134
Thus, the correct response is: Q1: 121; Q2: 127; Q3: 134