It takes a Christmas tree about 10 years to grow from seed to a size ready for cutting. We want to estimate the average height {1. of a 4-year Christmas tree which has been grown from a seed. Assume that the height of a 4-year tree is normally distributed. A sample of 2|] trees has a mean height 25.25 cm and a sample standard deviation 4.5 cm. This sample produces a condence interval {CI} for u of length 2.673. Determine the condence level of this Cl. 0 60% O 90% O 80% O 95% O 70%