IQ scores among the general population have a mean of 100 and a standard deviation of 15. A researcher claims that the standard deviation, o, of IQ scores for females is not equal to 15. A random sample of 15 IQ scores for females had a mean of 98 and a standard deviation of 11. Assuming that IQ scores for females are approximately normally distributed, is there significant evidence (at the 0.05 level of significance) to conclude that the researcher's claim is correct? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified below. (If necessary, consult a list of formulas.) (a) State the null hypothesis Ho and the alternative hypothesis H,. H O P Ho : D X S H, :0 0 (b) Determine the type of test statistic to use. Degrees of freedom: ] 0=0 030 020 (c) Find the value of the test statistic. (Round to three or more decimal places.) DA 0 O X 5 ? (d) Find the two critical values. (Round to three or more decimal places.) [ and (e) Can we support the claim that the standard deviation of IQ scores for females is not equal to 15? O Yes O No