# Anova and confidence intervals

Using the confidence intervals: 95%

Determine which groups differ in average shelf life.

A B C D

94 88 76 82

100 89 69 80

90 88 76 82

97 83 79 78

101 79 80 89

90 82 72 80

give test statistic, hypothesis, decision rule and hypothesis

https://brainmass.com/statistics/analysis-of-variance/anova-confidence-intervals-9762

#### Solution Preview

Null Hypothesis:

Ho: mu1 - mu2 = 0

Alternative hypothesis:

H1: mu1 - mu2 != 0

Mean calculations:

<A> = sum(A)/6 = 572/6 =95.33

<b> = 509/6 = 84.83

<C> = 452/6 = 75.33

<D> = 491/6 = 81.83

sum((A-<A>)^2) = 115.33

sum((B-<b>)^2) = 82.83

sum((C-<C>)^2) = 87.83

sum((D-<D>)^2) = 72.57

If t(calculated) > t(table) => Ho rejected

for any combination: (like A and B)

sqrt((1/n1) + ...

#### Solution Summary

The expert examines an ANOVA and confidence interval. The average shelf life of different groups are given. The solution answers the question(s) below.