Chapter 7 - Section 7.2 - Assess Your Understanding - Applying the Concepts - Page 378: 41a

$P(z > 0.25)$ $= 0.4013$

$\mu$ = 266, $\sigma$ = 16 Want to find $P( x > 270 )$ i) Convert 270 to a z-score: z = $\frac{x - \mu}{\sigma}$ z = $\frac{270 - 266}{16}$ z= 0.25 ii) $P(x > 270) = P(z > 0.25)$ $P(z > 0.25)$ $= 1 - P( z < 0.25)$ $= 1- 0.5987$ $= 0.4013$