Suppose the military has designed a new missile-guidance system.With the old system, 80% of missiles landed within thirty meters of the target at a range of five hundred miles.The military claims that the new system is better (that more than 80% of missiles will land within thirty meters at five hundred miles).Ten randomly-chosen, identical missiles will be launched using the new guidance system in order to test the null hypothesis that the accuracy rate of the new system is no better than that of the old system against the alternative hypothesis that the accuracy rate of the new system is better.

The military decides to increase the sample size to fifteen.What critical value should be used to control the maximum probability of Type I error at 10%?