Plz help this is hard plz

What is the average rate of change for this function for the interval from x=2 to x=4 ?

Suppose that one doll house uses the 1 inch scale, meaning that 1 inch on the doll house corresponds to 1/2 foot for life-sized objects. if the doll house is 108 inches wide, what is the width of the full-sized house that it's modeled after? in inches and feet.

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m