It is given in the question that
[tex]a = 6.1 m, b = 4.1 s, c = 87 m/s[/tex]
And the given expression is
[tex]d = \frac{a^3}{cb^2}[/tex]
Substituting the values of a,b and c, we will get
[tex]d = \frac{6.1^3}{87*4.1^2} = 0.1552m^2/s[/tex]
So with the given values of a,b and c, we will get
[tex]d=0.1552m^2/s[/tex]