Based on a sample of 55 salmon, we find the sample mean lifespan is 33.6 months. It is known that the population standard deviation is 1.5 months. Test the claim that for salmon the population mean lifespan is at most 35 months. Use an a = 0.10 significance level. Identify the following: Round results to two decimal places. f) The critical value is (give positive only if there are two): Hint: Is sigma known or unknown