Just need some quick help on finding the mean of group data.
I know the formula and how to get the answer, i.e. fx, but how do you go about it when the question is to do with ages, such as, 50 and over and also less than 33? How would you estimate a number to times by the frequency.
For the exact numbers, times by the frequency. For the 36-40 the midpoint then times by frequency... but what about the < and > parts since its ages?
Any help would be really appreciated, cheers.