Rhodesian ridgebacks are a large breed hound originally used to hunt lions in th

Question

1. Rhodesian ridgebacks are a large breed hound originally used to hunt lions in the regions of Africa now know as Zimbabwe. Adult male ridgebacks have weights that are normally distributed with a mean of 100 pounds and a standard deviation of 10 pounds while adult female ridgebacks have weights that are normally distributed with a mean of 80 pounds and a standard deviation of 7 pounds.
   1. A sample of 25 male adult ridgebacks are randomly selected and the sample mean weight is calculated. What is the mean and standard deviation for the sample mean?
   2. What is the probability that our observed sample mean weight for the adult males is less than 99 pounds?
   3. A sample of 16 female adult ridgebacks are randomly selected and the sample mean was calculated . what is the mean and standard deviation for the sample mean?
   4. What is the probability that our observed sample mean weight for the adult females is greater than 82 pounds?

Explanation / Answer

1. same as for the population: 100 pounds; SD(sample means) = SD/sqrt(n) = 10/sqrt(25) = 10/5 = 2 2. z = (99-100)/2 = -0.5, look that up in a table to get 0.3085 3. mean is 80 and SD is 7/sqrt(16) = 7/4 = 1.75 4. z=(82-80)/1.75 = 1.14, so look that up in a table to get 0.1265

Related Questions

Navigate

• Browse (All)
• Browse R
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.