About 30% of people age 50 to 60 suffer from mild depression. a researcher is interested in determining if a vitamin d supplement will increase or decrease the proportion of people that have mild depression. the researcher randomly selects 500 people between the ages of 50 and 60 and ask them to take a vitamin d supplement for 6 months. at the end of the six months, the participants are asked to complete a survey. a psychologist then classifies each participant as either depressed or not. the psychologist classifies 158 people as depressed. is the proportion of people that are classified as depressed different from 0.30? what is the null and alternative hypothesis?