(Ans. 77 10 Find the missing frequency given that the arithmetic mean of advertising expenditure is Rs. 5625. Advt. expenditure in Rs. 2000-3000 For the frequen 3000-4000 4000-5000 5000-6000 6000-7000 7000-8000 1: No. of companies 10 15 30 ? 65 25 .​