Question

Several neurosurgeons wanted to compare the operative time of a dynamic system (Z-Plate) to that of a static system (ALPS plate). The operative times, in minutes, for a random sample of 14 Dynamic systems and 6 Static systems are given below:

Dynamic: 370 345 360 450 510 505 445 335 295 280 315 325 490 500

Static: 430 455 445 490 455 535

The operative times in the Dynamic system come from a normal distribution with mean μ1 and variance .?21

The operative times in the Static system come from a normal distribution with mean μ2and variance .?22a.

Perform the equality of variances test at 10% significance level. Give hypotheses, test statistic, P-value, conclusion, and interpretation.

Perform the appropriate test at the 5% significance level to determine if the mean operative times in the two systems differ. Give hypotheses, test statistic, P-value, conclusion, and interpretation.

Answer 1

calculate mean and standard deviation

for dynamic

for static

F test for equality of variances

T test for two means

conclusion