convert analog pressure sensor mpx5500

can help me to convert analog pressure sensor to psi reading .... sensor 0.2v t0 4.7, 2.18psi t0 101.5psi. thank u

const int PressureInputPin = A0;
const float AnalogReferenceVoltage = 5.0;
const int MinReading = 0.2 * 1024.0 / AnalogReferenceVoltage;  // analogRead() value for 0.2V
const int MaxReading = 4.7 * 1024.0 / AnalogReferenceVoltage;  // analogRead() value for 4.7V
const float MinPressure = 2.18; // PSI
const float MaxPressure = 101.5; // PSI

float pressureInPSI = map(analogRead(PressureInputPin), MinReading, MaxReading, MinPressure, MaxPressure);

dcl3060: can help me to convert analog pressure sensor to psi reading .... sensor 0.2v t0 4.7, 2.18psi t0 101.5psi. thank u

may i know why minimum pressure = 2.18 and max pressure = 101.5?