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: ((19.7 × 9) ÷ 5) + 32 = (177.3 ÷ 5) + 32 = 35.46 + 32 = 67.46 °F