Part variability is critical in the manufacturing of ball bearings. Large variances in the size of the ball bearings cause bearing failure and rapid wear-out. Production standards call for a maximum variance of .0001 when the bearing sizes are measured in inches. A sample of 15 bearings shows a sample standard deviation of .014 inches. () Use a = .10 to determine whether the sample indicates that the maximum acceptable variance is being exceeded. (ii) Compute the 90% confidence interval estimate of the variance of the ball bearings in the population Do NOT use EXCEL O a) (i) Variance exceeds maximum variance requirement. (i) Between 0.00012 and 0.00042 O b) (1) Variance exceeds maximum variance requirement. (1) Between 0.00052 and 0.00092 O) ) Variance does not exceeds maximum variance requirement. (ii) Between 0.0012 and 0.0042 d) None of the answers are correct

IQ scores among the general population have a mean of 100 and a standard deviation of 14. A researcher claims that the standard deviation, o, of IQ scores for females is not equal to 14. A random sample of 24 IQ scores 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 H, and the alternative hypothesis H,. H, :0 H, :0 (b) Determine the type of test statistic to use. (Choose one) ▼ O=0 OSO (c) Find the value of the test statistic. (Round to three or more decimal places.) O