An advertisement for Cold-Over claims an 80% success rate in preventing a cold from developing if the patient starts the treatment immediately upon getting a sore throat or a runny nose. A random sample of 300 patients who are just developing symptoms are given Cold-Over, and are later checked to see if the treatment was successful. It is found that 235 of them found the treatment successful. Does the sample provide evidence that fewer than 80% of patients taking Cold-Over prevent a cold from developing if they take it as directed?