An industrial designer wants to determine the mean time it takes an adult to assemble an "easy to assemble" toy. A sample of 9 observations on assembly times yielded an average time of 20.83 minutes, with a sample standard deviation of 5.18 minutes. Using this data, the designer calculated a confidence interval for the mean assembly time to be 20.83 + 2.412. She forgot to state the confidence level but we can figure it out. What is the confidence level of this confidence interval