Past experience indicates that the time required for high school seniors to complete a standardized test is a normal random variable with a standard deviation of 6 minutes. Test the hypothesis that σ...

Past experience indicates that the time required for high school seniors to complete a standardized test is a normal random variable with a standard deviation of 6 minutes. Test the hypothesis that σ = 6 against the alternative that σ < 6="" if="" a="" random="" sample="" of="" the="" test="" times="" of="" 20="" high="" school="" seniors="" has="" a="" standard="" deviation="" s="4.51." use="" a="" 0.05="" level="" of="">