Solve the Problem $$\text { quadratic mean } = \sqrt { \frac { \sum x ^ { 2 } } { n } }$$

question 58

Multiple Choice

Solve the problem.
-The quadratic mean (or root mean square) is usually used in physical applications. In power distribution systems, for example, voltages and currents are usually referred to in terms of their root mean square value.
The quadratic mean of a set of values is obtained by squaring each value, adding the results, dividing by the
Number of values (n) , and then taking the square root of that result, expressed as $$\text { quadratic mean } = \sqrt { \frac { \sum x ^ { 2 } } { n } }$$ Find the root mean square of these power supplies (in volts) : 110, 105, 10, 72.

• A) 148.5 volts
• B) 74.3 volts
• C) 42.1 volts
• D) 84.3 volts

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Definitions:

Null Hypothesis

The presumption of no significant difference or association in a set of data, serving as a default position in hypothesis testing until evidence suggests otherwise.

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The measured levels of aluminum in a given sample or environment.

Test Statistic

A statistic used to estimate the parameter of interest in a statistical hypothesis test.

Kruskal-Wallis Test

A nonparametric statistical test used to compare three or more groups based on ranked data. It is an extension of the Mann-Whitney U test for more than two groups.