Oh thats good

Keep in mind that it is a binomial distribution. Let dying of combined causes be a success and dying of prostate cancer be a fail.

In 'wait and watch' the mean is 62/93=0.667

The standard deviation is $\displaystyle \sqrt{0.667\cdot(1-0.667)}=0.471$

The sample size is 93

In 'radical' the mean is 53/69=0.768

The standard deviation is $\displaystyle \sqrt{0.768\cdot(1-0.768)}=0.422$

The sample size is 69

The confidence interval for 'wait and watch' is $\displaystyle 0.667\pm\frac{0.471z}{\sqrt{93}}$

The confidence interval for 'radical' is $\displaystyle 0.768\pm\frac{0.422z}{\sqrt{69}}$