Statistics Examples
ClassFrequency10-14115-19320-24925-292ClassFrequency10−14115−19320−24925−292
Step 1
The lower limit for every class is the smallest value in that class. On the other hand, the upper limit for every class is the greatest value in that class.
ClassFrequency(f)LowerLimitsUpperLimits10-141101415-193151920-249202425-2922529ClassFrequency(f)LowerLimitsUpperLimits10−141101415−193151920−249202425−2922529
Step 2
The class midpoint is the lower class limit plus the upper class limit divided by 22.
ClassFrequency(f)LowerLimitsUpperLimitsMidpoint(M)10-141101410+14215-193151915+19220-249202420+24225-292252925+292ClassFrequency(f)LowerLimitsUpperLimitsMidpoint(M)10−141101410+14215−193151915+19220−249202420+24225−292252925+292
Step 3
Simplify all the midpoint column.
ClassFrequency(f)LowerLimitsUpperLimitsMidpoint(M)10-14110141215-19315191720-24920242225-292252927ClassFrequency(f)LowerLimitsUpperLimitsMidpoint(M)10−14110141215−19315191720−24920242225−292252927
Step 4
Add the midpoints column to the original table.
ClassFrequency(f)Midpoint(M)10-1411215-1931720-2492225-29227ClassFrequency(f)Midpoint(M)10−1411215−1931720−2492225−29227
