Shooting grade problem: A benchmark (hub) is at an elevation of 100.00. A backsite has a reading of 4.5′. A frontsite to the centerline of the road which has 3 inches of asphalt paving and 6 inches of crushed base has a reading of 3.75′. What is the s

Shooting grade problem: A benchmark (hub) is at an elevation of 100.00. A backsite has a reading of 4.5′. A frontsite to the centerline of the road which has 3 inches of asphalt paving and 6 inches of crushed base has a reading of 3.75′. What is the s