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Chapter 5: Q 95. (page 331)

Myspace versus Facebook A recent survey suggests that 85% of college students have posted a profile on Facebook,54% use Myspace regularly, and 42% do both. Suppose we select a college student at random and learn that the student has a profile on Facebook. Find the probability that the student uses Myspace regularly. Show your work.

Short Answer

Expert verified

P (My space/Facebook ) = 49.41%

Step by step solution

01

Step 1. Given Information

According to a recent survey, 85% of college students have a Facebook page, 54 percent use Myspace on a regular basis, and 42% use both.

02

Step 2. Concept used

Complement rule: P(notA)=1−P(A)

Conditional probability: P(B/A)=P(AandB)/P(A)

03

Step 3. Calculation

P(Facebook)=85%=0.85P(Myspace)=54%=0.54

Complement rule:

P(Facebook∩Myspace)=42%P(notlost)=1−P(lost)=1−0.13=0.87

Conditional probability is defined as follows: P(B/A)=P(AandB)/P(A)

Applying the conditional probability definition, we get:

P(Myspace/Facebook)=0.420.85=4285≈0.4941=49.41%

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Most popular questions from this chapter

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