The Irradiation of Food to Destroy Bacteria Is an Increasingly

question 88

Essay

The irradiation of food to destroy bacteria is an increasingly common practice. In order to determine which one of two methods of irradiation is best, a scientist took a random sample of 100 one-kilogram packages of minced meat and subjected 50 of them to irradiation method 1 and the remaining 50 to irradiation method 2. The bacteria counts were measured and the following statistics were computed. The scientist noted that the data were normally distributed. $$\begin{array} { | c | c | } \hline \text { Method 1 } & \text { Method 2 } \\\hline \bar { x } _ { 1 } = 86 & \bar { x } _ { 2 } = 98 \\\hline s _ { 1 } ^ { 2 } = 324 & s _ { 2 } ^ { 2 } = 841 \\\hline\end{array}$$ Determine whether these data are sufficient to infer at the 5% significance level that the two population variances differ.

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Definitions:

Blastopore

The opening that develops during early embryonic development, leading to the formation of the digestive tract in animals.

Deuterostomes

Deuterostomes are a major group in the animal kingdom characterized by the development of the anus from the first opening in the embryo, with humans and other vertebrates being examples.

Protostomes

A clade of animals characterized by embryonic development in which the mouth forms before the anus during early embryogenesis.

Cladogram

A diagram used in cladistics which shows relations among organisms based on the presence of shared characteristics not found in their ancestors.