Robin Dunbar, a leading anthropologist at Oxford University who studies social networks, has suggested that there is a magical number for social networks that humans can manage: any grouping larger than 150 people becomes overwhelming. With that in mind, a group of researchers at Facebook wanted to study more about how their average user manages their social networks. One study of 225 Facebook users found a mean of 338 friends. Facebook knows from prior studies of their users that the standard deviation is 44. Based on this information, what would be the point estimate for ? We are 95% confident that the mean number of friends that facebook users have is: between 335.07 and 340.93 between 250 and 426 between 332.13 and 343.87 between 294 and 382 between 329.2 and 346.8