Kaitlin is participating in a 5-day cross country biking challenge. she biked for 55,67,56,and 49 miles on the first four days. how many miles does she need to bike on the last day so that her average (mean) is 55 miles per day?

There are a total sales of 2,000 dollars on monday on tuesday sales dropped 10% on wednesday sales dropped another 20% compared with tuesday from wednesday to thursday sales increases by an equal amount to 25% of monday total sales what is the net change in dollars on total sales from monday to tuesday