From the data in the table, it can be predicted that the boiling point of propane is between 175 K and 200 K.
We know this because the density of propane decreases as the temperature increases. This is because the propane molecules are moving faster at higher temperatures, and therefore they are more likely to be spaced apart. At a certain temperature, the density of propane will be low enough that the molecules can escape into the gas phase. This temperature is the boiling point of propane.
The data shows that the density of propane at 175 K is 14.2 g/L and the density of propane at 200 K is 13.6 g/L and a suggestion that the boiling point of propane is somewhere between these two temperatures.
boiling point of propane = (T_1 + T_2) / 2
T_1 = temperature at which the density of propane is 14.2 g/L
T_2 = temperature at which the density of propane is 13.6 g/L
boiling point of propane = (175 K + 200 K) / 2
= 187.5 K
The prediction is that the boiling point of propane is approximately 187.5 K.