For the data shown here a Belt suspects the three grades are supplying the same results. Which statement(s) are true for proper Hypothesis Testing?

Question

Exhibit

Options

• AThe most appropriate Central Tendency to test is the Means
• BAn appropriate test to test Central Tendency is the Levene's test
• CAn appropriate test to test Central Tendency is the ANOVA test
• DAn appropriate test to test Central Tendency is the Mood's Median test

• A
  6% (3)
• B
  4% (2)
• C
  10% (5)
• D
  80% (40)

Explanation

Mood's Median test (D) is correct because the data involves grades, which are ordinal and likely non-normally distributed. When normality cannot be assumed, the median - not the mean - is the appropriate measure of central tendency, and Mood's Median test is the correct non-parametric method for comparing medians across three or more groups simultaneously.

Why the distractors are wrong:

• A is wrong - Means are appropriate only when data is continuous and normally distributed. Ordinal/non-normal data like grades calls for the median as the central tendency measure.
• B is wrong - Levene's test evaluates equality of variances (a test of spread/dispersion), not central tendency. It answers a different question entirely.
• C is wrong - ANOVA tests means and requires the assumption of normality. Since grades are ordinal and the normality assumption is suspect, ANOVA is not the proper tool here.

Memory tip: Think of it as a decision ladder - Is the data normal? If yes → ANOVA (means). If no → Is it ordinal or non-normal? → Mood's Median test. And remember "Levene's = Look at variance," never central tendency.

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