4．The partially completed tree diagram，where \(p\) and \(q\) are probabilities，gives information about Andrew＇s journey to work each day．
\includegraphics[max width=\textwidth, alt={}, center]{7d45bacd-20ac-49b4-8f3f-613edf3739f9-12_661_794_395_511}
\(R\) represents the event that it is raining
W represents the event that Andrew walks to work
\(B\) represents the event that Andrew takes the bus to work
\(C\) represents the event that Andrew cycles to work Given that \(\mathrm { P } ( B ) = 0.26\)
（a）find the value of \(p\) Given also that \(\mathrm { P } \left( R ^ { \prime } \mid W \right) = 0.175\)
（b）find the value of \(q\)
（c）Find the probability that Andrew cycles to work． Given that Andrew did not cycle to work on Friday，
（d）find the probability that it was raining on Friday．