Question Completion Status: A population is normally distributed with a standard deviation of 2.87. A sample of 8 items from the population yield a mean of 22.8. Determine the lower boundary of a 95% CI. Round to the nearest hundredth QUESTION 44 1 points Save Ans Practice z-alpha notation: Suppose that a confidence interval is to use 84.9% confidence. What is the value of alpha/2? No rounding QUESTION 45 1 points Save Answ t vs z 2: A sample of 6 data points with a sample mean of 56 is taken from a normal population with a standard deviation of 12 and is to be used to make a confidence interval. Which critical value is more appropriate, z or t? O a.z O b.t QUESTION 46 1 points Save Answ