Let's first compute the probability of one (or the first) trial, when the drawn is white.
Total balls = 13
White balls = 8
[tex]P(\text{whites)}=\frac{8}{13}[/tex]Now, everytime a replacement happens we will have the same amount of balls for the next trial. Therefore, the probability of whites will be multiplied for each trial:
[tex]P(\text{whites)}=(\frac{8}{13})^4=0.143[/tex]