Finding Arithmetic mean of this given data

The task is to find the Arithmetic mean of this data. I think it should be as follows line 1 for example (100+150)/2 * 14
line 2: (150+200)/2 * 18 then sum all the results and divide them be the number of days which is 144. What do you think?

aws02 said:

The task is to find the Arithmetic mean of this data. I think it should be as follows line 1 for example (100+150)/2 * 14
line 2: (150+200)/2 * 18 then sum all the results and divide them be the number of days which is 144. What do you think? View attachment 3524

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Your thinking is good. You do realize, however, that what you are calculating is the approximate weighted mean by assuming that each instance in a class is the midpoint of the class. Nothing wrong with that; good thinking, but I'd be happier if the problem had said approximate mean.

Well what I have learnt in my school is to create an additional mid value (x) column, fx column and find the mean by the equation : \(\displaystyle \frac{\sum fx}{\sum f}\)