Introduction to the Practice of Statistics

Step 1: Calculate the z-value at the upper endpoint of the interval: z = (1000 - 990)/14.6= .68 Step 2: Find the area under the curve to the left of the upper endpoint: P(z < .68) = .7517 Step 3: Calculate the z-value at the lower endpoint of the interval: z = (980 - 990)/14.6= - .68 Step 4: Find the area under the curve to the left of the ... ................
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