Write the null and alternative hypothesis of the following and determine if it is one-tailed or two-tailed. A bus company in Manila claims that the mean waiting time for a bus during rush hour is less than 12 minutes. A random sample of 30 waiting times has a mean of 15 minutes with a standard deviation of 4.8 minutesWrite the null and alternative hypothesis of the following and determine if it is one-tailed or two-tailed. A car manufacturer claims that the mean selling price of all cars manufactured is only P160,000. A consumer agency wants to test whether the mean selling price of all the cars manufactured exceeds P160, 000