It is desired to test the null hypothesis: population mean is equal to 55, against the alternative hypothesis: population mean is less than 55, using a = 0.10. The population in question is uniformly distributed with a standard deviation of 20. A random sample of 64 will be drawn from this population. If the population mean is really equal to 50, what is the probability that the hypothesis test would lead the investigator to commit a Type II error?