Math Problem Statement

STATISTICS AND PROBABILITY(Properties normal Curve)

Find the area between Z = 1.37 and Z = 2.55

Solution

To find the area between Z=1.37Z = 1.37 and Z=2.55Z = 2.55 on the standard normal distribution curve, we will use the Z-table or a standard normal distribution calculator.

Step 1: Find the cumulative probability for Z=2.55Z = 2.55

The Z-table gives the cumulative probability (area) to the left of a given Z-score. For Z=2.55Z = 2.55, we can find its cumulative probability.

Using a Z-table or standard normal calculator:

  • The cumulative probability for Z=2.55Z = 2.55 is approximately 0.9946.

Step 2: Find the cumulative probability for Z=1.37Z = 1.37

Similarly, for Z=1.37Z = 1.37:

  • The cumulative probability for Z=1.37Z = 1.37 is approximately 0.9147.

Step 3: Calculate the area between Z=1.37Z = 1.37 and Z=2.55Z = 2.55

The area between these two Z-scores is simply the difference between their cumulative probabilities:

Area=P(Z=2.55)P(Z=1.37)\text{Area} = P(Z = 2.55) - P(Z = 1.37) Area=0.99460.9147=0.0799\text{Area} = 0.9946 - 0.9147 = 0.0799

Final Answer:

The area between Z=1.37Z = 1.37 and Z=2.55Z = 2.55 is approximately 0.0799 or 7.99% of the total area under the standard normal curve.

Would you like more details on how the Z-table works, or any other explanations? Here are some related questions:

  1. What is the interpretation of a Z-score in terms of probability?
  2. How can you use the standard normal distribution to calculate probabilities for other Z-scores?
  3. What does the area under the curve represent in terms of standard normal distribution?
  4. How do you calculate probabilities for a different distribution (e.g., binomial)?
  5. What is the significance of a Z-score greater than 2 in a normal distribution?

Tip: When calculating areas in a normal distribution, always use the cumulative probability for the Z-scores and subtract to find the area between two points.

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Math Problem Analysis

Mathematical Concepts

Statistics
Probability
Properties of the Normal Curve
Standard Normal Distribution

Formulas

Cumulative probability for Z-scores using Z-table
Area = P(Z2) - P(Z1)

Theorems

Properties of the standard normal distribution
Empirical rule for normal distribution

Suitable Grade Level

Grades 11-12 and introductory college statistics