Question: Define the parameter of interest, and then use it to write the null and alternative hypotheses (in symbols) for the following situation. Nonprofit hospitals must provide a certain amount of charity care to maintain nonprofit, tax-exempt status. Although the amount differs by area, let's suppose that all such hospitals are required to provide charity services equivalent to 4% of net patient revenue. A legislator is concerned that there is inadequate enforcement of this regulation. He plans to audit a random sample of 30 nonprofit hospitals and assess the percentage of net patient revenue they spend on charity care. He will then test whether the population mean is at least 4%.