Let the probability that Shona is late be the complement of the probability that she is not late. Therefore, the probability that she is late is:

\(1 - 0.63 = 0.37\)

The probability that Shona is late if she catches the bus is:

\(0.8 imes 0.4 = 0.32\)

The probability that Shona is late if she cycles is:

0.2 imes x

Thus, the total probability that Shona is late is:

\(0.32 + 0.2x = 0.37\)

Solving for x:

\(0.2x = 0.37 - 0.32\)

\(0.2x = 0.05\)

\(x = rac{0.05}{0.2} = 0.25\)