Standard Normal areas Find the proportion of observations in a standard Normal distribution that satisfies each of the following statements.

a. z<2.46

b. 0.89<z<2.46

Short Answer

Expert verified

Part (a) Around 0.0069of the observations in a standard Normal distribution satisfy the statement.

Part (b) Around 0.1798 of the observations in a standard Normal distribution satisfy the statement.

Step by step solution

01

Part (a) Step 1: Given information

z<2.46

02

Part (a) Step 2: Concept

The formula used: Use the complement rule

03

Part (a) Step 3: Calculation

To find the equivalent probability, use the normal probability table in the appendix.

In the usual normal probability table for P(z<2.46)look for the row that starts with -2.4and the column that starts with.06

P(z<2.46)=0.0069

Therefore,

Around 0.0069 of the observations in a standard Normal distribution satisfyz<2.46

04

Part (b) Step 1: Given information

0.89<z<2.46

05

Part (b) Step 2: Calculation

To find the equivalent probability, use the normal probability table in the appendix.

The typical normal probability table for P(z<0.89)has a row that starts with 0.8and a column that starts with.09

And

The usual normal probability table for P(z<2.46)has a row that starts with 2.4and a column that starts with.06

Then

P(0.89<z<2.46)=P(z<2.46)P(z<0.89)=0.99310.8133=0.1798

Therefore,

Around 0.1798 of the observations in a standard Normal distribution satisfy0.89<z<2.46

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