Assume distribution of the weights of border collies is normally distributed, with population mean 38.5 lbs, and standard deviation 5.1 lbs.

1. Given that the weight of a particular border collie is under 40 pounds, what is the probability the weight of the border collie is over 38 pounds?
2. Find the 5th and 95th percentiles for average weight of 40 border collies.
3. If we randomly sample 5 border collies, what is the probability that at least two of them weigh over 38 pounds?
4. would it be appropriate to make a confidence interval for the true average weight of border collies? Explain.