The Records of a Department Store Show That 20% of Their

question 67

Short Answer

The records of a department store show that 20% of their customers who make a purchase return the merchandise for exchange. If the distribution of the random variable x describing the number of purchases is binomial,
a) what is the probability that at least 2 customers return the merchandise for exchange?
b) what is the expected number and standard deviation of customers who return the merchandise for exchange?

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Definitions:

Epidemiologic Transition

A phase of development witnessed by a sudden and stark increase in population growth rates brought by medical innovation in disease or disease control.

Mortality

The incidence of death within a population; the rate at which deaths occur in a particular population, typically expressed per thousand individuals per year.

Demographic Transition

The transition from high birth and death rates to lower birth and death rates as a country develops from a pre-industrial to an industrialized economic system.

Oral Rehydration Therapy

A simple, cost-effective treatment for dehydration, especially due to diarrhea, involving the oral intake of a solution of salts and sugars.