An automobile model is known to sustain no visible damage 25% of the time in 10-mph crash tests. a modified bumper design has been proposed in an effort to increase this percentage. let p denote the p

An automobile model is known to sustain no visible damage 25% of the time in 10-mph crash tests. a modified bumper design has been proposed in an effort to increase this percentage. let p denote the proportion of all 10-mph crashes with this new bumper that result in no visible damage. the hypotheses to be tested are h0: p = 0.25 (no improvement) versus ha: p 0.25. the test will be based on an experiment involving n = 20 independent crashes with prototypes of the new design. the natural test statistic here is x = the number of crashes with no visible damage. if h0 is true,