Essential Statistics

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Chapter 9: The Normal Probability Distribution 385
Figure 9-25: Area and probability value for P(1.5 ≤ z ≤ 2.5)
An alternative solution to the problem if we use the standard normal
distribution would be to use the table for -values between zero and some
other -value. This is equivalent to finding P(1.5   2.5) =
P(0   2.5) - P(0   1.5). From this standard normal table, for =
2.5, the corresponding value is 0.4938, and for = 1.5, the corresponding
value is 0.4332. Thus, the required area for P(1.5   2.5) = P (0  
2.5) - P(0   1.5) = 0.4938 – 0.4332 = 0.0606. This is shown
Figure 9-26.