Find the standard deviation for the set of data. {15, 17, 13, 20,7,7, 21, 22,4}

A. 7.09
B. 6.31
C. 6.39
D. 6.8

Your friend swims on the school team. in his first four races, his times are 24.7, 23.5, 25.6, and 27.2 seconds. which time listed for his next race would make the range larger?

Use set builder notation to represent the following set: { -3, -2, -1, 0}

Successful implementation of a new system is based on three independent modules. module 1 works properly with probability 0.96. for modules 2 and 3, these probabilities equal 0.95 and 0.90. compute the probability that at least one of these three modules fails to work properly.