Sample mean of Preservative A =108.7 hours
Sample mean of Preservative B =98.7 hour
Sample Standerd Deviation A=10.5 hours
Sample Standerd Deviation B=13.6 hour
a) State the null and alternative hypotheses to determine if the average number of hours until spoilage begins differs for the preservatives A and B?
b) Analyse sample variances in order to find which test would likely be most appropriate to employ to test the equality of the population means, pooled or unpooled?
c) Calculate the pooled variance and the value of the test statistic.