An Internet Service Provider (ISP) Has Randomly Selected a Sample

question 63

Multiple Choice

An internet service provider (ISP) has randomly selected a sample of 223 observations concerning values of the response variable Churn and several predictor variables based on customer activity during the most recently billed month. Here Churn equals Yes if a customer churned-left the internet service provider for another ISP-and equals No otherwise. The predictor variable MinutesOn is the average daily minutes the customer spent online. EmailSent is the average daily number of emails the customer sent from the email address provided by the ISP. ServCalls is the number of times the customer called for service. Below is part of the classification tree they derived from the data collected in the study. Of the sampled customers who spent an average of less than 511 minutes online per day and placed at least 3 service calls, what is the sample proportion of those who did not churn?

• A) .078
• B) .471
• C) .529
• D) .571
• E) .922

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Definitions:

Mitotic Activity

The process and rate of cell division in which a single cell divides to produce two identical daughter cells.

Stratum Basale

The deepest layer of the epidermis, responsible for generating new skin cells and containing melanocytes, which produce melanin that gives skin its color.

Albinism

A genetic disorder characterized by a lack of melanin pigment in the skin, hair, and eyes, resulting in a very pale appearance and sensitivity to sunlight.

Melanin

A pigment that gives human skin, hair, and eyes their color and offers protection against UV radiation.