v Question Completion Status: What is the critical value for a 90% confidence interval? O a. 1.645 O b. 2.326 O c. 2.576 O d. 3 QUESTION 47 1 points Save A CI (Z) calc 7: A population is normally distributed with a standard deviation of 3.23. A sample of 23 items from the population yield a mean of 27.4. Determine the lower boundary of a 90% Cl. Round to the nearest hundredth QUESTION 48 1 points Save Ar T CV 1: What is the critical value for a 98% confidence interval using a t-distribution with a sample size of 20?? O a. 2.539 O b. 2.326 O c. 2.528 Click Save and Submit to save and submit. Click Save All Answers to save all answers. Save All Answers Save and Sub