First, let's put the data set in order from least to greatest.
9, 15, 6, 10, 11, 6 → 6, 6, 9, 10, 11, 15
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Find the median is finding the middle number of a data set.
6, 6, 9, 10, 11, 15
Their is not middle in this data set but to find the median we can find what the middle number is between 9 and 10.
Median is 9.5
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Find the mean by adding all the numbers and dividing it by how many numbers their are.
6 + 6 + 9 + 10 + 11 + 15 = 57
57 / 6 = 9.5
Mean is 9.5
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Best Regards,
Wolfyy :)