E. Coli bacteria were added to 15 petri dishes and they were incubated for 24 hours....

E. Coli bacteria were added to 15 petri dishes and they were incubated for 24 hours. The “soap” dishes contained a solution prepared from ordinary soap; the “control” dishes contained a solution of sterile water. The number of bacteria colonies present in each dish after 24 hours are given below:Soap: 76 27 16 30 26 46 6Control: 30 36 66 21 63 38 35 45The numbers of bacteria colonies in the soap dishes come from a normal distribution with mean μ1 and variance .?21The numbers of bacteria colonies in the control dishes come from a normal distribution with mean μ2 and variance .?22

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

b. Perform the appropriate test at the 5% significance level to determine if dishes with soap have lower mean bacteria levels. Give hypotheses, test statistic, P-value, conclusion, and interpretat

Solutions

Expert Solution

calculate mean and standard deviation

for soap(1)

for control(2)

F test for equality of variances

T test for two means

orchestra answered 1 year ago

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