Instruction 15-14
Recent Studies Have Found That Australian Children Are

question 108

Multiple Choice

Instruction 15-14
Recent studies have found that Australian children are more obese than in the past. The amount of time children spent watching television has received much of the blame. A survey of 100 ten-year-olds revealed the following with regards to weights and average number of hours a day spent watching television. You are interested in testing whether the average number of hours spent watching TV and weights are independent at 1% level of significance.
| TV Hours |
$$\begin{array} { | l | c | c | c | c | } \hline \text { Weights } & 0 - 3 & 3 - 6 & 6 + & \text { Total } \\\hline \text { More than 10 kg overweight } & 1 & 9 & 20 & 30 \\\hline \text { Within 10 kg of normal weight } & 20 & 15 & 15 & 50 \\\hline \text { More than 10 kg underweight } & 10 & 5 & 5 & 20 \\\hline \text { Total } & 31 & 29 & 40 & 100 \\\hline\end{array}$$
-Referring to Instruction 15-14,the degrees of freedom of the test statistic are

• A) 9.
• B) 1.
• C) 4.
• D) 2.

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Definitions:

Energy Quality

A measure of an energy source's ability to do useful work; high-quality energy can be converted to work with high efficiency.

Sunlight

is the natural light of the sun, essential for photosynthesis in plants and influencing Earth's climate and weather patterns.

Electromagnetic Radiation

A form of energy that is propagated through space or through a material medium in the form of electromagnetic waves, such as light, radio waves, and X-rays.

Ultraviolet Waves

Electromagnetic waves with wavelengths shorter than visible light, harmful to skin and eyes but essential for Vitamin D synthesis in humans.