A random sample of 23 observations with a mean of 90 is selected from a normally distributed population. Assume the population standard deviation is 23. 1. In developing a(n) 80% confidence interval estimate for the population mean, determine the following values: a) [Do not round ] Point Estimate = 90 b) [2 decimal places] Significance level (o() = 0.20 Round the critical value to two (2) decimal places and use the rounded value to calculate the remaining parts. C) [Enter a positive value] Critical value = 1.28 d) [3 decimal places] Standard Error of the Mean = 4.796 e) [1 decimal place ] Margin of Error = 6.1 f) [1 decimal place] Lower Confidence Limit = 83.9 9) [1 decimal place] Upper Confidence Limit = 96.1 2. How large a sample is required to keep the margin of error within 4 units with 80% confidence? Report your answer as an integer. 45