Answer:
3.375 °C
Step-by-step explanation:
Mean temperature for first 7 days = 4 °C
⇒ Total temperature over first 7 days = 4 °C × 7 = 28 °C
Temperature on 8th day = -1 °C
[tex]\sf mean=\dfrac{\textsf{sum of all the numbers}}{\textsf{amount of numbers}}[/tex]
Therefore, mean temperature for first 8 days:
= [28 - 1] ÷ 8
= 27 ÷ 8
= 3.375 °C