If all people named Barry are nice, and the crowd contains 24 people named Barry, then 1*24=<<24*1=24>>24 of these people are nice.
If only half of people named Kevin are nice, and the crowd contains 20 people named Kevin, then 0.5*20=<<0.5*20=10>>10 of these people are nice.
If three-fourths of people named Julie are nice, and the crowd contains 80 people named Julie, then (3/4)*80=<<3/4*80=60>>60 of these people are nice.
If 10% of people named Joe are nice, and the crowd contains 50 people named Joe, then 0.1*50=<<0.1*50=5>>5 of these people are nice.
In total, the crowd contains 24+10+60+5=<<24+10+60+5=99>>99 people who are nice.
#### 99