1. A sample is taken at n = 49 from a normal population at = 10. a) Calculate x b) Calculate the 99% CI

2. A random sample of 10 observations from a normal population, of known standard deviation equal to 5, gives an average of 20 a) Calculate the standard error b) Why are t-values (Student's law) not taken for this calculation? c) Calculate the limits of the 95% CI

3.We have a sample of which we only know n = 10, s = 13 and x = 65. Calculate 95% CI.

4. A sample of 20 animals was randomly selected from a breeding population and then sacrificed for autopsy and weighing several organs. The average weight in grams of the hearts x = 49.35 with a variance s² = 81.1801. a) Calculate the limits of 95% CI assuming you know = 8.50 b) Calculate the bounds of 95% CI assuming you don't know