How to find the solution, add relevant course topics and add references.

The answer should be in three parts: solutions, add course relevant topics and third is references.

A random sample of adults was asked to respond to a survey about whether they use their cell phones to shop for a specific item. One question, summarized in the table below reflecting probabilities, asked each respondent to choose whether or not they use a cell phone app to shop. The major age groupings were under 40 or 40 years or older. Find the probability that an adult randomly chosen from the group uses a cell phone app to shop. Age Yes No Under 40 0.40 0.20 0.60 40 or Older 0.30 0.40 0.50 0.50 1.00 O A. 60% B. 50% O C. 0.50% O D. 40%