Abusiness major wants to determine whether the variation in advertising costs of hair salons is different from the variation in advertising costs of nail salons. he surveys several businesses and finds the standard deviation in monthly advertising costs is $23 for 12 hair salons, and $43 for 8 nail salons. what is the test value for this hypothesis test? test value: round your answer to two decimal places. at the 0.05 level of significance, what is the critical value? critical value: round your answer to two decimal place