[tex]\text{Binomial Distribution: } P(X = r) = \binom{n}{r}(p)^{r}(1 - p)^{n - r}[/tex]
[tex]P(X < 9) = 1 - P(X = 9) - P(x = 10)[/tex]
[tex]P(X = 9) = \binom{10}{9}(0.75)^{9}(0.25)[/tex]
[tex]P(X = 10) = \binom{10}{10}(0.75)^{10}[/tex]
[tex]P(X < 9) = 1 - \binom{10}{9}(0.75)^{9}(0.25) - \binom{10}{10}(0.75)^{10}[/tex]
[tex] \approx 0.755974769...[/tex]
