Question 379936
Here {{{mu = 25}}} and {{{sigma = 4.25}}}.


a) {{{P(X >= 27) = P((X - mu)/sigma >= (27 - 25)/4.25 = 0.47)}}}.  Hence {{{P(X >= 27) = P(Z >=0.47)}}}.



b)  {{{P(26 < X < 30) = P((26 - 25)/4.25 < (X - mu)/sigma =Z < (30 - 25)/4.25)}}}.  Hence P(26 < X < 30) = P(0.235 < Z < 1.176)

In either case, just use a usual standard normal table to find the probabilities.