Answer:
[tex]F=175.2N[/tex]
Explanation:
The relationship of between fundamental frequency, density of the string, length and tension of the string is:
[tex]L=\frac{1}{2f} \sqrt{\frac{F}{\frac{L}{m} } }[/tex]
where L/m is the linear density.
make F the subject of the formula
[tex]F=4L^{2}f^{2} \frac{L}{m}[/tex]
substitute the values
[tex]F=4*0.805^{2} *65.4^{2} *(1.58*10^{-2} )\\F=175.2N[/tex]