A marine biologist wants to use a parrotfish for research purposes as she believes that the variability of weights among parrotfish is small. From a random sample of 50 parrotfish, she found that their mean weight is 6.3 pounds with a standard deviation of 2.4 pounds. She will only use the parrotfish if there is evidence that the variance of their weights is less than 4 pounds. Formulate an appropriate hypothesis test to determine if there is enough evidence that the weight is small enough for the marine biologist to use them in her research.