The Amount of Sunshine Illuminating a Wall of a Building

question 59

Multiple Choice

The amount of sunshine illuminating a wall of a building can greatly affect the energy efficiency of the building. The solar radiation striking a vertical wall that faces east is given by the formula where R ₀ is the maximum solar radiation possible, is the angle that the sun makes with the horizontal, and is the direction of the sun in the sky, with = 90 ^o when the sun is in the east and = 0 ^o when the sun is in the south. What percentage of R ₀ is striking the wall when is equal to 60 ^o and the sun is in the southeast?
Round the answer to the nearest integer.

• A)40 %
• B)59 %
• C)20 %
• D)25 %
• E)35 %

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Definitions:

Null Hypothesis

A statement used in statistical testing which proposes that no significant difference or effect exists between certain characteristics of a population.

Type I Error

The error of rejecting a true null hypothesis, also known as a "false positive."

Null Hypothesis

An assertion or proposition in statistics that indicates no significant difference or effect, serving as the default assumption to test against.

Type II Error

The error that occurs when the null hypothesis is falsely accepted, failing to detect an effect or difference when one actually exists.