We are to convert the temperature that Jessica was able to read on a cool autumn day from °C to °F. To solve this, we need to recall the formula in converting temperature from °C to °F and this is shown below: F = (9/5)C + 32, Jessica reads 18°C and substitute this to C in the formula such as: F = (9/5)18 + 32 F = 32.4 + 32 , perform addition of 32.4 and 32 F = 62.4 °F