The headwaters of a river are at an elevation of 1,229 feet and the river flows 373 miles to the ocean. Determine the river's average gradient in ft/mi. Give your answer with 2 decimals.

3.29ft/mi

Explanation:

The gradient of a river is the slope through which a river flows. It measures the vertical drop in elevation of river to the horizontal distance.

 Mathematically;

  River gradient =  

 Elevation  = 1229ft

Horizontal distance  = 373miles

  River gradient  =   = 3.29ft/mi