Skip to main content
Pearson+ LogoPearson+ Logo
Ch. 2 - Transmission Genetics
Sanders - Genetic Analysis: An Integrated Approach 3rd Edition
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172Not the one you use?Change textbook
Chapter 2, Problem 7a

If a chi-square test produces a chi-square value of 7.83 with 4 degrees of freedom,
In what interval range does the P value fall?

Verified step by step guidance
1
Step 1: Understand the problem. The chi-square test is used to determine whether there is a significant difference between the observed and expected data. Here, the chi-square value is 7.83, and the degrees of freedom (df) are 4. We need to determine the range of the P-value.
Step 2: Recall the relationship between the chi-square value, degrees of freedom, and the P-value. The P-value is determined by comparing the chi-square value to a chi-square distribution table for the given degrees of freedom.
Step 3: Locate the row in the chi-square distribution table corresponding to 4 degrees of freedom. Identify the chi-square values in this row that are closest to 7.83. These values will help determine the range of the P-value.
Step 4: Find the P-value intervals associated with the chi-square values identified in Step 3. The P-value decreases as the chi-square value increases, so the range will correspond to the interval between the two closest chi-square values.
Step 5: Conclude that the P-value falls within the interval determined in Step 4. This interval provides an estimate of the probability that the observed data could occur under the null hypothesis.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Chi-Square Test

The chi-square test is a statistical method used to determine if there is a significant association between categorical variables. It compares the observed frequencies in each category to the expected frequencies, which are calculated under the assumption of no association. A higher chi-square value indicates a greater discrepancy between observed and expected values.
Recommended video:
Guided course
02:48
Chi Square Analysis

Degrees of Freedom

Degrees of freedom (df) in a chi-square test refer to the number of independent values that can vary in the analysis. For a chi-square test of independence, the degrees of freedom are calculated as (number of rows - 1) × (number of columns - 1). In this case, with 4 degrees of freedom, it indicates the complexity of the data being analyzed.
Recommended video:

P-Value

The P-value is a measure that helps determine the significance of the results from a statistical test. It represents the probability of observing the test results, or something more extreme, under the null hypothesis. A lower P-value (typically less than 0.05) suggests that the observed data is unlikely under the null hypothesis, leading to its rejection.
Recommended video:
Guided course
03:08
Drosophila P Element