1. The following data represents the sales (in R million) for 200 companies involved in the development of infrastructure for the 2010 World Cup:
   Sales (in R million)
   20-<30
   30-<40
   40-<50
   50-<60
   60-<70
   70-<80
   80-<90
   90-<100
   Total
   Frequency
   10
   25
   30
   30
   40
   30
   25
   10
   200
   Calculate the mean for grouped data using the formula 

Answer rating: 100% (QA)

To calculate the mean for grouped data you need to foll... View the full answer