In a 2020 article, Ryan Motz and his colleagues investigated how youth justice system contact affected their offending at age 18. Using pairs of twins, they found that those who had justice system contact through spending a night in jail, being issued an antisocial behavior order, or having an official record promoted crime and resulted in increased offending. Let's say you have a sample of 20 eighteen-year-old males who have been in juvenile institutions at least once before they were eighteen. The mean offending rate in the last six months for these 20 males was 18 with a standard deviation of 4. Build a 99% confidence interval around this point estimate. How to calculate this using excel