Question 870233
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Hi
Response time has mean M=8.8 minutes with standard deviation 2.1 minutes
random sample of 32 response time is taken:  2.1/sqrt(32) = .3712
a) z = .2/.3712 = .5388, P(z &#8804; 9) = 70.50%
b) z = -.8/.3712 = -2.1552, P(z &#8805; -2.1552) = 98.44% 
c) P(z &#8804; -2.1552) = 1.56%, P(8 &#8804; x &#8804; 9) = 96.88%