stats question

10. A salesperson at a small corner store believes he sells an average of at least $800 worth of items each day. Daily sales are assumed to be normally distributed with a standard deviation of $120. A random sample of 100 days is taken to test this claim. (a) Formulate the null and alternative hypotheses to test the claim. (b) Determine the critical value of sales required to reject the claim at a 0: = .05 level of signicance. Sketch the distribution of sales under your null hypothesis from (a) and identify the region of rejection and associated probability. (c) Find the probability 6 of a Type II error if the population mean is actually $772 per day. Provide a sketch of distribution(s) to explain the Type II error. (d) Identify the factors that will aect and explain how changes to each factor you identify will change ,8