Stephanie was injured in a car accident and was rushed to the emergency room. She received stitches for a facial wound and treatment for a broken finger. Under Stephanie's PPO plan, emergency room care at a network hospital is $75$ percent covered after the member has met an annual deductible of $$310.$ Assume that Stephanie went to a hospital within her PPO network. Her total emergency room bill was $$970.$

a$.$ What amount did Stephanie have to pay?

b$.$ What amount did the PPO cover?