Answer
$$ P(z<5.0)=22.96 % $$
It means only 22.96 % rainy days have rainfall of pH below 5.0.
Work Step by Step
Step 1:
We are looking for proportion of rainy days that have rain fall with pH below 5.0. So using our z- score formula and or knowledge , we have :
$$P(z<5.0)=\frac{5.0-5.4}{0.54}$$
Step 2: Doing arithmetic, we have :
$$P(z<5.0)=-0.74$$
Step 3: Converting our z core into percentage by using our Z core table:
$$P(z<5.0)=0.2296$$
Step 4: Converting our decimal into percent by multiplying by 100%:
$$ P(z<5.0)=22.96 % $$
Step 5: Conclusion:
Only 22.96 % rainy days have rainfall of pH below 5.0
