1. The distribution of Intelligence Quotient (I.Q.) scores measured for 100 students in a test is as follows:I.Q.*40-5050-6060-7070-8080-9090-100Number of Students102020151520* The data is recorded with origin as 40, i.e. students with I.Q. between 80 and 90 are included in the first interval. The intervals included the upper class value but not the lower.Find: Arithmetic Mean, Median, First and Third Quartiles, 90th percentile and 6th Decile.