Which graph represents a phase shift of pi/2 units right for the graph of y = COS X?
A. y = csc x
B. y = sin x
C. y = cos(x+pi/2)
D. y = sec x

Solve - pv + 40 < 65 for v solve 7w - 3r = 15 for r

1. there are 25 students who started computer programming in elementary school and 25 students who started computer programming in middle school. the first group had a mean final project grade of 95% and the second group had a mean final project grade of 92%. the line plot shows the differences after 10 rerandomizations. determine whether the difference in the means of the two groups is significant based on the line plot. explain your answer.

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?