Inflation based on the wholesale price index (WPI) dropped to 5.09% for the week ended October 28 from 5.41% in the previous week, due to the drop in prices of essential commodities.Essential commodities like pulses, sugar, fruits, vegetables saw dip in prices, while cereal prices rose marginally.Pulses prices declined by 0.6%, while fruits and vegetables became cheaper by 0.5% and sugar, khandsari and gur prices fell by 0.2%.Cereal prices rose slightly by 0.1%.This was the fourth week in a row wherein the inflation stood above the 5% mark.