At least how many schools have participated for more than 1 year and less than 6 years? 4 schools
8 schools
10 schools
20 schools
The following box plot below shows the number of years during which 40 schools have participated in an interschool swimming meet.

Aparticular telephone number is used to receive both voice calls and fax messages. suppose that 25% of the incoming calls involve fax messages, and consider a sample of 25 incoming calls. (a) what is the expected number of calls among the 25 that involve a fax message?