The weight of laboratory butterflies follows a Normal distribution, with a mean of 50 grams and a standard deviation of 3 grams. What percentage of the butterflies weigh between 47 grams and 53 grams?

1.) 99.7%
2.) 95%
3.) 68%
4.) 47.5%
5.) 34%

Out of the 150 students at a summer camp, 72 signed up for canoeing. there were 23 students who signed up for trekking, and 13 of those students also signed up for canoeing. use a two-way table to organize the information and answer the following question: approximately what percentage of students signed up for neither canoeing nor trekking?