Allergic reactions to poison ivy can be miserable. plant oils cause the reaction. researchers at allergy institute did a study to determine the effects of washing the oil off within 5 minutes of exposure. a random sample of 1000 people with known allergies to poison ivy participated in the study. oil from the poison ivy plant was rubbed on a patch of skin. for 500 of the subjects, it was washed off within 5 minutes. for the other 500 subjects, the oil was washed off after 5 minutes. the results are summarized in the table. reaction within 5 minutes after 5 minutes row total none 420 50 470 mild 60 330 390 strong 20 120 140 column total 500 500 1,000 what is the probability that a person selected at random had no reaction. express your answer as a decimal rounded to the nearest hundredth.