Answer
a)68.26%
b)2.28%
c)95%
d)95.44%
e)0.13%
Work Step by Step
a)Using the table, the probability of z being between -1 and 1 is equal to the probability of z being less than 1 minus the probability of z being less than -1, which is: 0.8413-0.1587=0.6826=68.26%.
b)Using the table, the probability of z being more than 2 is equal to 1 minus the probability of z being less than 2, which is: 1-0.9772=0.0228=2.28%.
c)Using the table, the probability of z being between -1.96 and 1.96 is equal to the probability of z being less than 1.96 minus the probability of z being less than -1.96, which is: 0.9750-0.0250=0.95=95%.
d)Using the table, the probability of z being between -2 and 2 is equal to the probability of z being less than 2 minus the probability of z being less than -2, which is: 0.9772-0.0228=0.9544=95.44%.
e)Using the table, the probability of z being more than 3 is equal to 1 minus the probability of z being less than 3, which is: 1-0.9987=0.0013=0.13%.