A hungry college student just finished eating a large cheese and pepperoni pizza from Doug's Pizza Palace and felt there wasn'
t enough cheese and pepperoni on it as he has had large pizzas with more cheese and pepperoni on it from this place in the past. This led him to wonder what the average weight of a large cheese and pepperoni pizza was at Doug's Pizza Palace. Doug ordered a large cheese and pepperoni pizza from Doug's Pizza Palace on 15 randomly selected days during a particular term and weighed each before eating it. Suppose all conditions are met for inference using the one-sample t-methods. The student constructed a 95% confidence interval for the population mean using the one-sample t-methods. How many degrees of freedom does the t critical value have?