An increasing number of consumers believe that they have to look out for themselves in the marketplace. According to a survey conducted y the Yankelovich Partners for USA Weekend magazine, 60% of all consumers have called an 800 or 900 telephone number for information about some product. Suppose a random sample of 25 numbers is contacted and interviewed about their buying habits.
a) what is the probability that15 or more of these consumers have called an 800 or 900 telephone number for information about some products?