Acceleration due to gravity above the surface of earth at a height \(h\) is given \(g^{\prime}=g\left(1-\frac{2 h}{R_\theta}\right)\) here, \(g^{\prime}=0.98 \,g\)
\(\Rightarrow 0.98=1-\frac{2 h}{R_e}\)
\(\Rightarrow \frac{2 h}{R_e}=0.02\)
\(h=0.01 R_e\)
\(=0.01 \times 6400 \,km\)
\(=64 \,km\)