Seven out of 10 teenagers aren't getting enough sleep. 

"Teenagers need more sleep than the typical adult does," explained Dr. Dixie Harris, a specialist in sleep medicine, pulmonary disease and critical care with Intermountain Healthcare. "The recommendation from the National Sleep Foundation is 8-10 hours."

What percentage of teenagers would you guess get the recommended amount of sleep? 25%? 50%?

"Seventy percent of teenagers do not get that amount of sleep," Harris said.