In the 1970’s it was generally assumed that the mean birth w…
In the 1970’s it was generally assumed that the mean birth weight of Angus beef cattle was 75 lb. A researcher believes that, due to selection for increased size and growth rate in Angus, the average birth weight is now greater than 75 lb. He obtains a random sample of n = 144 birth weights of Angus calves and calculates a sample mean of 85 lb and a sample standard deviation of 10 lb. State the null and alternative hypothesis that the researcher wants to test.