The data give sample means: X, = 5.4250, X, = 4.5125 and sample variances: s; = 0.5536, s, = 0.5784 а) Calculate the pooled estimate for the variance common to the male and female populations. b)...

Extracted text: The data give sample means: X, = 5.4250, X, = 4.5125 and sample variances: s; = 0.5536, s, = 0.5784 а) Calculate the pooled estimate for the variance common to the male and female populations. b) Estimate the standard error of the difference between the population means. c) Construct a 95% confidence interval for the difference between the two population means.


Extracted text: The extent to which X-rays can penetrate tooth enamel had been suggested as a suitable mechanism for differentiating between males and females in forensic medicine. Listed below in appropriate units are the 'spectropenetration gradients' for eight female and teeth and eight male teeth: Male (X1) Female (X2) 4.9 5.4 5.0 5.5 5.4 6.6 6.3 4.3 4.8 5.3 3.7 4.1 5.6 4.0 3.6 5.0