Question

How do I find the mean and the ungrouped mean on a calculator and by hand?

Answer 1

Answer: [Note: By mean we are referring here as grouped mean as the other option is stated to be ungrouped mean]

A) In the case of grouped data, there are intervals r classes with given frequencies, Grouped mean is obtained by denoting a midpoint for each of the interval, multiplying it with the corresponding class frequency, summing each of them up and dividing the sum by total frequency. It is denoted by x_bar = sum(xi*fi) /sum(fi); where xi = the midpoint of the i-th interval, fi = frequency of the i-th class, i=1(1)n.

B) In the case of ungrouped data, mean is obtained by summing each of the given observations and dividing the sum by the number of observations in the dataset. It is denoted by x_bar = sum(xi) /n ; where xi = the i-th observation in the dataset, n= total number of observation, i=1(1)n