$\mu = 2$
$\sigma^2 = 25$
$\sigma = 5$
$Z_1 =$$\large \frac{1 - 2}{5} = -0.2$
$Z_2 =$$\large \frac{4 - 2}{5} = 0.4$
$P (1 < X < 4) = \phi(0.4) - \phi (-0.2)$
$P (1 < X < 4) = \phi(0.4) - (1 - \phi (0.2)) $
$P (1 < X < 4) = 0.6554 - (1 - 0.5793)$
$P (1 < X < 4) = 0.2347$