Several insurance companies are trying to promote additional health insurance coverage. In order to offer complete information, insurance providers connect with customers via phone or email. It is estimated that approximately 87% of total customers are contacted by phone, half of whom purchase the additional health insurance coverage, and 12% of the customers who are not contacted by phone purchase the additional coverage anyway. Given the information about the purchase patterns of additional health insurance coverage, what is the probability that a phone call is received by a customer who purchases additional health insurance coverage?