I attached a Diagram for this problem.
We star considering the system is in equlibrium, so
Fm makes [tex]90-(\theta+5)[/tex] with vertical
Fm makes 70 with vertical
Applying summatory in X we have,
[tex]\sum F_x = 0[/tex]
[tex]W+1.4-Fm cos(70)[/tex]
We know that W is equal to
[tex]W= 0.06*100N = 6N[/tex]
Substituting,
[tex]Fm cos (70) = W+1.4N[/tex]
[tex]Fm cos (70) = 6N + 1.4N[/tex]
[tex]Fm = \frac{7.4}{cos(70)}[/tex]
[tex]Fm = 21.636N[/tex]
For the second part we know that the reaction force Fj on deltoid Muscle is equal to Fm, We can assume also that [tex]\beta = \theta[/tex]