When one person shouts at a football game, the sound loudness at the center of the field is 55 dB. When all the people shout together, the loudness...

When one person shouts at a football game, the sound loudness at the center of the field is 55 dB. When all the people shout together, the loudness increases to 105 dB. Assume that each person is about the same distance from the center of the field and can generate the same level of sound intensity. How many people are at the game?