## Introductory Statistics 9th Edition

a. From the given normal distribution, μ=1650 and σ= 320. For x =1950 : z = $\frac{1950-1650}{320}$ = 0.9375 $P(x \lt 1950)$ = $P(z \lt 0.9375 )$ = .9332 approximately. b. For x =900 : z = $\frac{900-1650}{320}$ = -0.2.3438 For x =1300: z = $\frac{1300-1650}{320}$ = -1.0938 $P(900 \leq x \leq 1300)$ = $P(1\leq z \leq 2.75)$ = 0.137-0.0095 = .1275 approximately. = 12.75%