What portion of Catalina's $4,000 paycheck is taxable by California?

The entire amount of Catalina's $4,000 paycheck is taxable by California. California taxes personal income, and wages earned from employment are considered taxable income. This income is subject to state income tax regardless of the source, which includes salaries, wages, bonuses, and other forms of compensation. Therefore, the full amount of Catalina's paycheck, which is $4,000, must be reported and is liable for taxation under California law.

This understanding aligns with California's approach to income taxation, where all forms of income earned by residents are typically included in the taxable income calculation.