A Petronas station collected data from the day's receipts, recording the gallons of petrol each customers purchased. The following table list the frequency distribution of petrol purchase by all customers on this one day at this Petronas station. Gallons of petrol Number of customers 0 to less than 4 31 4 to less than 8 78 8 to less than 12 49 12 to less than 16 81 16 to less than 20 117 20 to less than 24 13 How many customers were served on this day at this Petronas station? (1 Mark) Il. Calculate the estimated mean of petrol purchase by all customers. (2 Marks) Find the relative frequency of petrol purchase is between 12 to less than 16. (2 Marks)