Question

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Answer 1

• c) 11.5

Explanation:

Total frequencies:

• 6 + 15 + 20 + 7 + 2 = 50

Median group is the containing the middle - 25th and 26th frequencies. This is the 11-15 interval.

Estimated median formula:

• Estimated Median = L + ((n/2) − B)/G* w, where

• L - lower class boundary of the group containing the median = 10.5
• n - total number of values = 50
• B - cumulative frequency of the groups before the median group = 6 + 15 = 21
• G - frequency of the median group = 20
• w - group width = 5

Substitute values and work out the number:

• Estimated Median = 10.5 + (50/2 - 21)/20*5 = 11.5