Consumers turned to their mobile devices in growing numbers and increasing frequency throughout 2010. Text messaging led as the top mobile activity, with 68% of American mobile subscribers texting in 2010. A polling firm contacts an SRS of 1200 people chosen from the population of American mobile subscribers.
If the sample were repeated many times, what would be the range of the sample proportions of mobile subscribers who have texted, according to the 95 part of the 68-95-99.7 rule?