From the question, we are given the information that the mean temperature for the first 7 days in January was 3 °C. This means that the total temperature for the first 7 days in January was:
= 3°C × 7
= 21°C
We are also told that the temperature on the 8th day was 5°C. To calculate the the mean temperature for the first 8 days in January, we add the total temperature for the 8 days and then divide by 8.
The total temperature for the 8 days will be: = 21°C + 5°C = 26°C.
The mean temperature for the first 8 days in January will now be:
