The following data table is taken from a study. It is a cross-classification of stress and income.

The following data table is taken from a study. It is a cross-classification of stress and income. Here "stressed" means that the person reported that most days are extremely stressful or quite stressful; "not stressed" means that the person reported that most days are a bit stressful, not very stressful, or not at all stressful.

a) What is the probability that someone in this study is stressed or has low income (or both)?

b) What is the probability that someone in this study is stressed and has low income?

c) What is the probability that someone in this study with low income is stressed?

d) What is the probability that someone in this study that is stressed has low income?