A sample of 20 students take Math 203 was randomly selected to evaluate the results on the Math 203 final exam. The average for the sample was 74 with a standard deviation of 7.5. Determine the 95% confidence interval for students taking the exam. Previous studies indicate a standard deviation of 8.3. (Assume that the population standard deviation is the 8.3.) Assume the population is approximately normally distributed.
|Answer the following:|
|1. Determine the type of confidence interval (z, t, or proportion).|
|2. State the confidence interval. Round your answer to 1 decimal place.|
|3. Based on your confidence interval for the population (true) mean, do you feel the average is too low and the exam needs to be changed? Explain your answer|