In order to calculate the rate of change we need to divide the variation of temperature by the variation of time. Since the time is given to us in a 12 h format (am/pm), we first need to convert it to 24 h. To do that we sum the time that is "pm" by 12, we have:
time2 = 3 + 12 = 15
Therefore the rate of change in temperature is:
rate = variation of temp / variation of time
rate = (temp final - temp init) / (time final - time init)
