Math Problem Statement

In 4 decimal places, find the probability that a standard normal random variable Z falls between −2.00 and −0.44.

Solution

To find the probability that a standard normal random variable ZZ falls between 2.00-2.00 and 0.44-0.44, we need to calculate the cumulative distribution function (CDF) values for these two points and subtract them.

The standard normal distribution, denoted as ZN(0,1)Z \sim N(0, 1), has a mean of 0 and a standard deviation of 1.

Step-by-Step Calculation:

  1. Find the CDF value for Z=2.00Z = -2.00:

    The CDF value, Φ(2.00)\Phi(-2.00), represents the probability that the random variable ZZ is less than 2.00-2.00.

  2. Find the CDF value for Z=0.44Z = -0.44:

    Similarly, Φ(0.44)\Phi(-0.44) is the probability that ZZ is less than 0.44-0.44.

  3. Calculate the probability P(2.00<Z<0.44)P(-2.00 < Z < -0.44):

    This probability can be found using the difference between the two CDF values: P(2.00<Z<0.44)=Φ(0.44)Φ(2.00)P(-2.00 < Z < -0.44) = \Phi(-0.44) - \Phi(-2.00)

Using the standard normal distribution table or a calculator to find the CDF values:

  • Φ(2.00)0.0228\Phi(-2.00) \approx 0.0228
  • Φ(0.44)0.3300\Phi(-0.44) \approx 0.3300

Compute the Probability:

P(2.00<Z<0.44)=0.33000.0228=0.3072P(-2.00 < Z < -0.44) = 0.3300 - 0.0228 = 0.3072

Thus, the probability that a standard normal random variable ZZ falls between 2.00-2.00 and 0.44-0.44 is 0.3072.

Summary:

The probability P(2.00<Z<0.44)P(-2.00 < Z < -0.44) to four decimal places is 0.3072.


Do you want more details on any part of this solution, or do you have any questions?

Here are 5 related questions for further exploration:

  1. What is the probability that ZZ falls between 0 and 1 in a standard normal distribution?
  2. How do you calculate the Z-score for a given data point?
  3. What are the properties of the standard normal distribution?
  4. How can we use the standard normal distribution to calculate probabilities for non-standard normal distributions?
  5. What is the relationship between the normal distribution and the empirical rule?

Tip: Always remember that the area under the curve of a probability distribution function represents probabilities. For the standard normal distribution, this total area is equal to 1.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Normal Distribution
Cumulative Distribution Function (CDF)
Probability Calculation

Formulas

Standard Normal Distribution CDF

Theorems

-

Suitable Grade Level

Advanced High School or College