Using it's concept, the mean monthly membership fee is of $61.62.
The mean of a data-set is given by the sum of all observations in the data-set divided by the number of observations.
For this problem, the observations are given by:
$65,$50,$44,$86,$90,$50,$35,$110,$70,$50,$35,$60,$56.
There are 13 observations, hence the mean is given by:
M = (65 + 50 + 44 + 86 + 90 + 50 + 35 + 110 + 70 + 50 + 35 + 60 + 56)/13 = $61.62.
Hence the mean monthly membership fee is of $61.62.
More can be learned about the mean of a data-set at https://brainly.com/question/24628525
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