The table shows the amount of snow, in cm, that fell each day for 30 days. Amount of snow (s cm) Frequency 0 ï‚„ s < 10 8 10 ï‚„ s < 20 10 20 ï‚„ s < 30 7 30 ï‚„ s < 40 2 40 ï‚„ s < 50 3 Work out an estimate for the mean amount of snow per day