Department Store
a Large Department Store Records the Number of Returns

question 15

Essay

Department store
A large department store records the number of returns per day in women's dresses for reasons such as wrong size; husband didn't like it,color,etc.The manager of the women's dresses department recalls from her statistics class in college that the Poisson distribution might describe such events.A random sample of 150 days is taken.The number of returns per day in the sample as well as the observed frequencies are shown below: $$\begin{array} { | c | c | } \hline \begin{array} { c } \text { Number of } \\\text { Returns Per Day }\end{array} & \begin{array} { c } \text { Observed } \\\text { Frequency }\end{array} \\\hline 0 & 21 \\1 & 37 \\2 & 44 \\3 & 30 \\4 & 14 \\> 4 & 4 \\\hline\end{array}$$
-She tests the hypothesis that returns per day are Poisson distributed with a population mean equal to 1.90.Her significance level is 0.05.Determine the calculated value of the chi-square test statistic.

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Definitions:

Ribose

The 5-carbon sugar present in RNA and in important nucleoside triphosphates such as ATP.

Leader Sequences

Short sequences of amino acids at the beginning of the synthesis of a protein that signal where in the cell it should be localized.

Ribosomes

Cellular structures responsible for protein synthesis, found in both eukaryotic and prokaryotic cells.

Translation

The conversion of information provided by mRNA into a specific sequence of amino acids in a polypeptide chain; process also requires transfer RNA and ribosomes.