Four balls numbered 1, 2, 3, and 4 are placed in a bowl. After the balls are mixed, one is chosen, its number is noted, then it is replaced. Doing the experiment repeatedly many times, find the variance and standard deviation of the numbers on the balls.​

The perimeter of a stage is 116 feet. it is 17 feet wide. how long is it?

Find the exact value of each of the following. in each case, show your work and explain the steps you take to find the value. (a) sin 17π/6 (b) tan 13π/4 (c) sec 11π/3

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?