In the year 1992, 7 measurements were made in the Inner Bay; these averaged 8.6 with a standard deviation of 4.5. Should the Student’s t distribution be used to find a 95% confidence interval for the mean filtration rate for the Inner Bay? If so, find the confidence interval.
 

The minimum possible value is 4, which is greater than two sample standard deviations below the sample mean. The minimum possible value is 0, which is less than two sample standard deviations below the sample mean. It is impossible to observe a value that is two or more sample standard deviations below the sample mean. It is possible to observe a value that is two or more sample standard deviations below the sample mean. The sample may not come from a normal population. The sample may come from a normal population. The 95% confidence interval for the mean filtration rate for the Inner Bay is (4.438, 12.761). The 95% confidence interval for the mean filtration rate for the Inner Bay is (5.438, 10.761).