What is the point estimate for the confidence interval and how did you determine this? The confidence interval is [419.55, 480.45]. A random sample of 36 households was selected as part of a study on water usage in a small community, and the number of gallons was recorded for each household in the sample for the 2nd quarter of 2021. The data were approximately normally distributed with a mean of 450 gallons and a sample standard deviation of 90. A researcher intends to determine a 95% confidence interval for the population mean water usage during the period.