what is the vertex of this function ?

Customers are used to evaluate preliminary product designs. in the past, 93% of highly successful products received good reviews, 51% of moderately successful products received good reviews, and 14% of poor products received good reviews. in addition, 40% of products have been highly successful, 35% have been moderately successful and 25% have been poor products. round your answers to four decimal places (e.g. 98.) what is the probability that a product attains a good review? (b) if a new design attains a good review, what is the probability that it will be a highly successful product? (c) if a product does not attain a good review, what is the probability that it will be a highly successful product?