Math Problem Statement
let z be the standard normal variable. find the value of z if z satisfies P(-z<Z<z)=0.2468
Solution
To solve for in the probability statement , we need to understand that this represents the probability that a standard normal variable lies within the symmetric interval about the mean 0 of the standard normal distribution.
Steps:
-
Symmetry of the Standard Normal Distribution: Since the standard normal distribution is symmetric, the probability corresponds to the cumulative probability from to , and the tails of the distribution (outside this interval) must sum up to the remaining probability.
-
Relation to the Standard Normal Table: The total probability under the normal curve is 1. If , then the probability in the tails (outside the interval ) is: Since the distribution is symmetric, the probability in each tail is:
-
Using the Standard Normal Table: Now we look for the value of such that the cumulative probability from to is . This corresponds to the cumulative distribution function (CDF) for .
-
Finding : Using a standard normal distribution table or calculator, we find the z-value that gives a cumulative probability of 0.3766.
The z-value that corresponds to a cumulative probability of 0.3766 is approximately .
Thus, (we consider the positive value since the interval is symmetric).
Final Answer:
The value of that satisfies is approximately .
Would you like further details on this, or do you have any additional questions?
Here are some related questions:
- What is the meaning of a standard normal distribution?
- How do you use the z-table to find probabilities?
- What is the relationship between probability and the cumulative distribution function (CDF)?
- How do you calculate probabilities for non-standard normal distributions?
- What is the significance of symmetric intervals in normal distribution problems?
Tip: When working with z-values and probabilities, always check whether the problem refers to a one-tailed or two-tailed scenario, as it affects the interpretation of the probability.
Ask a new question for Free
By Image
Drop file here or Click Here to upload
Math Problem Analysis
Mathematical Concepts
Probability
Standard Normal Distribution
Symmetry in Normal Distribution
Formulas
P(-z < Z < z) = Probability of Z lying within the interval (-z, z)
Cumulative probability: P(Z < z)
Theorems
Standard Normal Distribution Theorem
Properties of Symmetry in Normal Distribution
Suitable Grade Level
Grades 10-12 (High School)
Related Recommendation
Find z for P(Z > z) = 0.57 in Normal Distribution
Find the Z-Score Corresponding to an Area of 0.9456 under the Normal Curve
Find the Z-Value for a Cumulative Probability of 0.3012 in Normal Distribution
Find the Z-score for Cumulative Probability of 0.9463 in Standard Normal Distribution
Find z0 for Given Area Between Z-Scores in Normal Distribution