Derive a formula for this slope

Job ID: 32925897

Budget: ₹600 – ₹1,500 INR

i have built a sensor which outputs voltage as per the input
need to convert the voltage to some meaningful value
bellow is the some sample table. need a formula for this
Voltage>Expected Value
2.38>3200
2.3>2238
2.08>1192
1.32>572
0.57>355

1-2% error is ok
Remember this is not a school project so need an actual formula and need to know how to get that formula
attached is the ploted graph for the value for better understanding