Shelly biked 21 miles in 4 hours.

What is Shelly’s average speed in miles per hour?

The median of a data set is the measure of center that is found by adding the data values and dividing the total by the number of data values that is the value that occurs with the greatest frequency that is the value midway between the maximum and minimum values in the original data set that is the middle value when the original data values are arranged in order of increasing (or decreasing) magnitude

Can someone explain to me how to do

Yesterday, george drank 1 small bottle and 2 large bottles, for a total of 1,372 grams. the day before , he drank 1 small bottle and 1 large bottle, for the total of 858 grams. how many grams does each bottle hold?