Configure a Transmitter for a particular process application

A differential pressure transmitter is calibrated 0 to 80 inches of water and transmits a 4 to 20 mA dc signal. This transmitter is placed across an orifice plate which is sized to create 80 inches of water differential 6 gallons per minute. What is the flow rate when the signal is 13 mA dc?
For the equipment described in the preceding question, what will the signal be if the flow rate is 4 gpm?
Assume the line used in Questions 1 and 2, is a 1/2-inch schedule 40 pipe (IV = 0.622 inches). find the orifice bore used to satisfy the conditions given if the measured fluid is water at 60 Deg F
The best choice of orifice taps in the preceding problem would be:
A 2-inch schedule 40 line (lD = 2.067) is used to carry gasoline (Specific Gravity = 0.75). The flow rate is measured with an orifice plate (d = 1.034) and pipe taps are used. At full flow rate, a differential pressure of 50 inches of water is produced. What is the approximate full flow rate in gpm?