Answer: B.56
Explanation:
We know that to calculate the mean we need to add up all the observations, then divide by the number of observations .
The mean numbers of turkey vultures between March 10 and March 14 is given by :-
[tex]\text{Mean}=\frac{\text{Sum}}{\text{number of observations}}\\\\=\frac{65+60+64+62+64}{5}=\frac{315}{5}\\\\\Rightarrow\ \text{Mean}=63[/tex]
The mean numbers of great blue herons between March 10 and March 14 is given by :-
[tex]\text{Mean}=\frac{\text{Sum}}{\text{number of observations}}\\\\=\frac{8+6+7+8+8}{5}=\frac{37}{5}\\\\\Rightarrow\ \text{Mean}=7.4\approx7[/tex]
The difference between the mean numbers of turkey vultures and great blue herons observed at Hornsby Bend between March 10 and March 14=[tex]63-7=56[/tex].