Assignment #3
Sampling Distributions
1. Forest type 1 has an average diameter of 35 cm and a standard deviation of 6 cm. Forest type 2 has an average diameter of 25 cm and a standard deviation of 5 cm. The distribution of the diameters is normal in both types.
1. What is the probability that a sample mean will be greater than 36 cm from type 1 if 20 trees are measured?
2. What is the probability that a sample variance is less than 19 cm2 from type 1 if 20 trees are measured?
3. Find the probability that the sample mean computed from 20 measurements from type 1 will exceed the sample mean computed from 25 measurements from type 2 by at least 11 cm.
4. Find the probability that the ratio of sample variances (S12/S22) computed from 10 measurements from type 1 (S12) and 8 measurements from type 2 (S22) will exceed 5.4.
