A Scientist Was Interested in the Success of a Newly $\quad$

question 15

Multiple Choice

A scientist was interested in the success of a newly developed sleep aid called 'Night Owl' on time taken to fall asleep and quality of sleep. She recruited 30 participants who were randomly allocated to receive either a dose of Night Owl or a placebo. The scientist measured the mean time taken for each participant to fall asleep (minutes) and the quality of their sleep (measured on a scale of 1 (poorest quality) to 10 (best possible quality) ) over the course of one week.
-What does the output below show?
$\quad$$\quad$ Box's Test of Equality
$\quad$$\quad$$\quad$ of Covariance
$\quad$$\quad$$\quad$$\quad$ Matrices ${ } ^ { a }$
$\begin{array}{|l|r|}\hline \text { Box's M } & .229 \\\text { F } & .070 \\\text { df1 } & 3 \\\text { df2 } & 141120.000 \\\text { Sig. } & .976\\\hline\end{array}$
Tests the null hypothesis that the observed covariance matrices of the dependent variables are equal across groups.

a. Design:
Intercept + Drug Bartlett's Test of Sphericity ${ } ^ { a }$
$\begin{array}{|l|r|}\hline \text { Likelihood Ratio } & .000 \\\text { Approx. Chi-Square } & 101.046 \\\text { df } & 2 \\\text { Sig. } & .000\\\hline\end{array}$

Tests the null hypothesis that the residual covariance matrix is proportional to an identity matrix.
a. Design: Intercept + Drug

• A)The assumption of equality of covariance matrices has been violated.
• B)The assumption of sphericity has been met.
• C)The covariance matrices are not significantly equal.
• D)The covariance matrices are roughly equal as assumed.

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Definitions:

Winning Bids

The highest offers made in an auction or tender process that secure the right to purchase goods or services.

High-value

Attributes or items considered to have a significant worth or importance, either in monetary terms or in qualitative aspects such as quality or utility.

Winning Price

The final bid amount that secures an item or service in an auction; the price at which the auction is won.

Low-value

Pertaining to items or services that are considered to have less worth or importance, often reflected in their low cost.