According to a recent survey high school girls average 100
According to a recent survey, high school girls average 100 text messages daily (The Boston Globe, April 21, 2010). Assume the population standard deviation is 20 text messages. Suppose a random sample of 50 high school girls is taken.
a. What is the probability that the sample mean is more than 105?
b. What is the probability that the sample mean is less than 95?
c. What is the probability that the sample mean is between 95 and 105?

Membership TRY NOW
  • Access to 800,000+ Textbook Solutions
  • Ask any question from 24/7 available
    Tutors
  • Live Video Consultation with Tutors
  • 50,000+ Answers by Tutors
OR
Relevant Tutors available to help