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Gnagey's Gknives claim they will last at least year 10 years without needing to be sharpened. Consumer Reports randomly samples 42 knives, and calculates that they need to be sharpened on average in 9.25 years. Based on other knife sharpening studies, suppose that the population standard deviation is known to be 1.7 years. Consumer Reports wants to conduct a hypothesis test at 0.01 level of signicance. If you were to use the critical value approach, what is the critical value for this hypothesis test? (Round to two decimal places e.g. 7.46] (Note: if the test is two-tailed I will accept either the positive or the negative critical value)