Identify the station and elevation of the lowest point on the curve.

Learning Goal: I’m working on a civil engineering question and need an explanation and answer to help me learn.Describe the perception-reaction process in order.
A curve formed by a Back Tangent with a bearing of S 30° W and a Forward Tangent with a bearing of N 85° W, has a degree of 15° defined by 100 feet of arc. The station of the point of intersection is 205+30.
Calculate the station of PT.
Calculate the shortest distance between PC and PT.
Calculate shortest distance between the point of intersection and the curve.
A grade g1 of -1.50% intersects grade g2 of +2.50% and an equal-tangent curve is desired. The design speed is 50 mph. What is the minimum length the curve must have, to comply with stopping sight distance requirements? (Use both methods, the precise and the estimation with K)
A grade g1 of -4.00% intersects grade g2 of +1.00% at a vertex whose station and elevation are 158+10.45 and 2,920.09 ft, respectively. An equal-tangent parabolic curve 800 ft long has been selected to join the two tangents. Compute the station and elevation of PVT.
Compute the elevation of the first full station inside the curve.
Identify the station and elevation of the lowest point on the curve.
Describe the change in radius that occurs on a spiral curve (a drawing can be used here).
Consider that the station of the Spiral to Curve (STA SC) is 453+77.35 for a two-lane highway (one per direction) with a normal crown of 2% and a design super elevation of 6%. Each lane is 12 feet, and the design speed is 60
mph. Determine the station where the tangent runout starts.
What is “decision sight distance”?
The following mass diagram shows the data from a highway project. The Project has a free haul distance of 160’ and the contractor decided that the maximum distance of overhaul will be 400’. Determine and identify the following:
The free haul volume
The overhaul volume
The average overhaul distances
The amount of borrow material
The amount of waste material
Please provide the results and show them on the mass diagram.
Requirements: Answers need to clear and full explanation