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 fewer than 3 service calls, what is the sample proportion of those who churned?
A) .067
B) .078
C) .529
D) .861
E) .885

Question

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 fewer than 3 service calls, what is the sample proportion of those who churned?
A) .067 
B) .078 
C) .529 
D) .861 
E) .885

Quizplus · Accepted Answer

15/192 = .078 is the proportion of sampled customers with MinutesOn < 511 and ServCalls < 3 who churned.

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