Both SmithCo and Jones Inc. sell widgets. SmithCo's sales last month equalled 1000 and it charged a price of $2. This month Jones Inc. reduced the price it sells its brand of widgets from $2.10 to $2, and SmithCo saw a reduction in the quantity of widgets is sold, down to 900 units. What is the cross elasticity of demand between the two brands of widgets? Using the midpoint method