307 Diamonds Were Sampled and Randomly Sorted into Three Groups

question 15

Multiple Choice

307 diamonds were sampled and randomly sorted into three groups of diamonds. These diamonds were randomly assigned to one of the three organizations, or groups (HRD, GIA, or IGI) , that certify the appraisal of diamonds. A study was conducted to determine if the average size of
Diamonds reported by these three certification groups differ. A completely randomized design was used and the Bonferroni multiple comparison results are shown below.

Bonferroni All-Pairwise Comparisons Test of CARAT by CERT

$\begin{array} { l c c } \text { CERT } & \text { Mean } & \text { Bonferroni Groups } \\ \text { HRD } & 0.8129 & \text { A } \\ \text { GIA } & 0.6723 & \text { B } \\ \text { IGI } & 0.3665 & \text { C } \end{array}$
Alpha $0.05$

Give the population mean(s) which are in the statistically largest group.

• A) µHRD & µGIA
• B) µIGI
• C) µGIA
• D) µHRD

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Definitions:

Pyroclastic Material

Fragmented material ejected during volcanic eruptions, including ash, bomb, lapilli, and volcanic blocks, which varies in size, shape, and composition.

Mudflows

Rapid downhill movement of water-laden earth materials, primarily composed of fine-grained soils and clays, which can cause significant erosion and damage.

Pyroclastic Flow

A hot, fast-moving and deadly mixture of gases, ash, and volcanic material produced by explosive eruptions.

Scoria

A highly vesicular, dark colored volcanic rock that may or may not contain crystals, typically formed from the cooling of lava.