prop.test(5,500,0.02,alternative="l",conf.level=0.9)

        1-sample proportions test with continuity correction

data:  5 out of 500, null probability 0.02
X-squared = 2.0663, df = 1, p-value = 0.07529
alternative hypothesis: true p is less than 0.02
90 percent confidence interval:
0.00000000 0.01878006
sample estimates:
   p
0.01