A set of average city temperatures in October are normally distributed with a mean of 20.
6
∘
C
20.6
∘
C20, point, 6, degrees, start text, C, end text and a standard deviation of
2
∘
C
2
∘
C2, degrees, start text, C, end text.
What proportion of temperatures are between
1
8
∘
C
18
∘
C18, degrees, start text, C, end text and
20.
6
∘
C
20.6
∘
C20, point, 6, degrees, start text, C, end text?