To find the mean number of fire hydrants, we first need to add up the total number of hydrants across all the streets and then divide by the number of streets.
From the information provided, we have:
- Oak Street: 0 hydrants
- Rose Street: 1 hydrant
- Fir Street: 2 hydrants
- Pine Street: 3 hydrants
- Elm Street: 4 hydrants
- Cedar Street: 5 hydrants
- Lemon Street: 6 hydrants
- Maple Street: 7 hydrants
Now, let's sum these counts:
\[ 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28 \]
There are 8 streets in total.
Now, we calculate the mean:
\[ \text{Mean} = \frac{\text{Total number of hydrants}}{\text{Number of streets}} = \frac{28}{8} = 3.5 \]
Thus, the mean number of fire hydrants per street is \( 3.5 \).