A Machine Produces Pipes Used in Airplanes

question 5

Essay

A machine produces pipes used in airplanes. The average length of the pipe is 16 inches. The acceptable variance for the length is .3 inches. A sample of 25 pipes was taken. The average length in the sample was 15.95 inches with a variance of .4 inches.
a.Construct a 95% confidence interval for the population variance.
b.State the null and alternative hypotheses to be tested.
c.Compute the test statistic.
d.The null hypothesis is to be tested at the 5% level of significance. State the decision rule for the test.
e.What do you conclude about the population variance?

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Definitions:

Genetic Drift

A mechanism of evolution that involves random changes in the frequency of alleles within a population over time.

McDonald-Kreitman Test

A method used in molecular evolution to compare the ratio of non-synonymous to synonymous substitutions in a gene between species, assessing natural selection.

Homologous Gene

Genetic sequences that are shared by different species and have been inherited from a common ancestor.