Question

Two methods of Natrella’s research in 1963, A and B, were used in a determination of the latent heat of fusion of ice. The investigator wanted to find out by how much the methods differed. The data (TwoMethods.xlsx) give the change in total heat from ice at -0.72°C to wafer 0°C in calories per gram of mass.

(a) Assuming that the population variances are equal, compute the pooled variance of the two sample.

(b) Assuming that the population variances are equal, is there evidence of a difference in calories per gram of mass between the two methods at a 0.05 significance level?

(c) Obtain the confidence interval of the average difference between the two methods at a 95% confidence level, and make a statistical decision based on the interval.

(d) Compare the results from (b) and (c).

A	B
79.98	80.02
80.04	79.94
80.02	79.98
80.04	79.97
80.03	79.97
80.03	80.03
80.04	79.95
79.97	79.97
80.05
80.03
80.02
80.00
80.02

Answer 1