The F Index is a scale that measures the readability of a particular English passage. For example, a F index of 11.5 indicates that the material is about 11th grade level. A random sample of 64 passages by a well know horror author yielded a mean F index of 9.5 with a standard deviation of 0.8. Construct and interpret a 95% confidence interval for the mean F index for all the books by this horror author.