The problem asks us to determine whether to reject or fail to reject the null hypothesis based on the given ANOVA table and to calculate the effect size. The ANOVA table provides the sums of squares (SS), degrees of freedom (df), mean squares (MS), and the F statistic.

Probability and StatisticsANOVAHypothesis TestingF-statisticEffect SizeEta-squared
2025/4/23

1. Problem Description

The problem asks us to determine whether to reject or fail to reject the null hypothesis based on the given ANOVA table and to calculate the effect size. The ANOVA table provides the sums of squares (SS), degrees of freedom (df), mean squares (MS), and the F statistic.

2. Solution Steps

First, we determine whether to reject the null hypothesis. The F-statistic is given as F=5.83F = 5.83. The degrees of freedom for the numerator (between groups) is dfbetween=2df_{between} = 2, and the degrees of freedom for the denominator (within groups) is dfwithin=41df_{within} = 41.
To make a decision, we need to compare the calculated F-statistic to a critical F-value at a chosen significance level (alpha). Since the alpha level is not specified, we will commonly use α=0.05\alpha = 0.05. We look up the critical F-value for dfbetween=2df_{between} = 2 and dfwithin=41df_{within} = 41 at α=0.05\alpha = 0.05. Using an F-distribution table or calculator, Fcritical(2,41,0.05)3.22F_{critical}(2, 41, 0.05) \approx 3.22.
Since the calculated F-statistic (5.835.83) is greater than the critical F-value (3.223.22), we reject the null hypothesis.
Next, we calculate the effect size, specifically eta-squared (η2\eta^2), which represents the proportion of variance in the dependent variable that is explained by the independent variable. The formula for eta-squared is:
η2=SSbetweenSStotal\eta^2 = \frac{SS_{between}}{SS_{total}}
From the ANOVA table, we have SSbetween=60.72SS_{between} = 60.72 and SStotal=274.33SS_{total} = 274.33. Plugging these values into the formula, we get:
η2=60.72274.330.221\eta^2 = \frac{60.72}{274.33} \approx 0.221

3. Final Answer

We reject the null hypothesis. The effect size, measured by eta-squared, is approximately 0.
2
2
1.

Related problems in "Probability and Statistics"

The problem provides a table of observed prices ($Y$) and available quantities ($X$) of a product in...

Regression AnalysisLinear RegressionCorrelation CoefficientCoefficient of DeterminationScatter Plot
2025/6/7

The problem provides a frequency distribution table of marks obtained by students. Part (a) requires...

ProbabilityConditional ProbabilityWithout ReplacementCombinations
2025/6/5

The problem is divided into two questions, question 10 and question 11. Question 10 is about the fre...

Frequency DistributionCumulative FrequencyOgivePercentileProbabilityConditional ProbabilityCombinations
2025/6/5

A number is selected at random from the integers 30 to 48 inclusive. We want to find the probability...

ProbabilityPrime NumbersDivisibility
2025/6/3

The problem describes a survey where 30 people answered about their favorite book genres. The result...

PercentagesData InterpretationPie ChartFractions
2025/6/1

The problem asks us to determine if there is a statistically significant difference in promotion rat...

Hypothesis TestingChi-Square TestContingency TableStatistical SignificanceIndependence
2025/6/1

We are given a contingency table showing the number of students from different majors (Psychology, B...

Chi-Square TestContingency TableStatistical InferenceHypothesis Testing
2025/6/1

The problem describes a scenario where a pizza company wants to determine if the number of different...

Chi-Square TestGoodness-of-Fit TestHypothesis TestingFrequency DistributionP-value
2025/6/1

The problem asks to test the significance of three chi-square tests given the sample size $N$, numbe...

Chi-square testStatistical SignificanceDegrees of FreedomEffect SizeCramer's VHypothesis Testing
2025/5/29

The problem asks us to compute the expected frequencies for the given contingency table. The conting...

Contingency TableExpected FrequenciesChi-squared Test
2025/5/29