Reconsider the data from Exercise 10-10. Find a 95% confidence interval on the difference in mean force on the hands for the two activities. How would you interpret this CI? Is the value zero in the CI? What connection does this have with the conclusion that you reached in Exercise 10-10?

Exercise 10-10

An article in Industrial Engineer (September 2012) reported on a study of potential sources of injury to equine veterinarians conducted at a university veterinary hospital. Forces on the hand were measured for several common activities that veterinarians engage in when examining or treating horses. We will consider the forces on the hands for two tasks, lifting and using ultrasound. Assume that both sample sizes are 6, the sample mean force for lifting was 6.0 pounds with standard deviation 1.5 pounds, and the sample mean force for using ultrasound was 6.2 pounds with standard deviation 0.3 pounds (data read from graphs in the article). Assume that the standard deviations are known. Is there evidence to conclude that the two activities result in significantly different forces on the hands?