Chapter 5 - Section 5.6 - Assess Your Understanding - Applying the Concepts - Page 312: 27

$P(a~parent~owns~|~his~or~her~teenager~owns)=\frac{0.43}{0.79}\approx0.5443$

$79$% $=0.79$ $P(a~teen~owns)=0.79$ $P(a~teen~and~his~or~her~parent~own)=0.430$ Use the Conditional Probability Rule (page 288): $P(a~parent~owns~|~his~or~her~teenager~owns)=\frac{P(a~teen~and~his~or~her~parent~own)}{P(a~teen~owns)}=\frac{0.43}{0.79}\approx0.5443$