Question C.4: Find the area under the curve that is outside of two standar......

What the problem is asking for(Figure 1):

Appendix B Table A provides the right half of the area between the mean and z = + 2. To fi nd the area in the right tail, subtract the amount between the mean and z = + 2 from .5000(Figure 2):

Area under the right side of the curve:          .5000
Subtract the area from z 5 0 to z = + 2.00:  \underline{- .4772}

            .0228

The same amount will be in each tail, so the total area in both tails is 2(.0228) = .0456(Figure 3).

Another way to arrive at the same answer is to note that the area within two standard deviations of the mean is .9544, as shown previously, so the area outside of that is 1.0000 – .9544 = .0456.