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

question 70

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 223 sampled customers, what is the sample proportion of those who churned?

• A) .143
• B) .168
• C) .571
• D) .857
• E) .885

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Definitions:

Pupil

The opening in the center of the iris of the eye, through which light enters the eye to reach the retina.

Electromagnetic Energy

A form of energy that is propagated through space or matter, comprising electric and magnetic field components oscillating in phase and perpendicular to each other.

Optic Nerve

A cranial nerve that transmits visual information from the retina to the brain.

Blind Spot

An area on the retina without receptors that respond to light, where the optic nerve exits the eye, creating a spot where no image is detected.