The meteorological team conducted tests at 2:00, 10:00, 14:00, and 21:00 on a certain day, and the measured temperatures were 13°C, 16°C, 25°C, and 18°C. What is the average temperature in degrees Celsius throughout the day.
气象小组在某一天的2时、10时、14时、21时进行测试，测得的温度分别是13℃、16℃、25℃、18℃．全天的平均气温约是多少摄氏度．
<gadget id="calculator">13 + 16 + 25 + 18</gadget>
<output>72</output>

<gadget id="calculator">72 / 4</gadget>
<output>18</output>

<result>18</result>