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

question 25

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 at least 511 minutes online per day and sent an average of at least 7 emails per day from their ISP-provided email address, what is the sample proportion of those who churned?

• A) .078
• B) .143
• C) .200
• D) .571
• E) .778

---

Definitions:

Hypothesis

A proposed explanation for a phenomenon, based on limited evidence as a starting point for further investigation.

Neuron Theory

The principle that the nervous system is made up of discrete individual cells called neurons, which are the fundamental units of the brain and nervous system.

Axon Hillock

The conical structure at the junction between the axon and the neuron cell body where action potentials are generated.

Neural Bridge

A connection formed between different parts of the nervous system to facilitate communication or signal transmission.