The Fact That the Earth-Moon System Orbits the Sun (Covering

question 28

Multiple Choice

The fact that the Earth-Moon system orbits the Sun (covering 30° per month) while the Moon orbits Earth means that, compared to one lunar orbital (sidereal) period, the time between successive full Moons (the synodic month) is

• A) about 2 days longer.
• B) about 2 days shorter.
• C) about twice as long.
• D) zero because these periods are always the same, by definition.

---

Definitions:

Risk-Free Investment

An investment that is expected to return its original investment value without any loss.

Mean-Variance Criterion

The mean-variance criterion is a method for selecting investments that balance expected return against portfolio variance or risk.

Expected Return

The forecasted profit or loss from an investment over a specific period, often based on historical data or statistical models.

Standard Deviation

A measure of the dispersion or variability of a set of data points from their mean, used in finance to estimate the risk of an investment.