We are told that the mean temperature for the first 4 days in January was -2°C. The mean temperature for the first 5 days in January was -3°C.
Now we will find sum of temperatures on first four days of January by multiplying 4 by -2.


Now let us find sum of temperature on first 5 days of January.


Now we will subtract -8 from -15 to find temperature on the 5th day of January.


Therefore, temperature on the 5th day of January was
