According to Conversion formula above if you want to convert degrees Celsius to degrees Fahrenheit you have to multiply degrees Celsius by 9, divide the result by 5 and add 32 to it.
So you have: ((30.7 × 9) ÷ 5) + 32 = (276.3 ÷ 5) + 32 = 55.26 + 32 = 87.26 °F