Question: Improving the productivity of chickens. Farmers have discovered that more domestic chickens peck at objects placed in their environment, the healthier and more productive the chickens seem to be. White string has been found to be a particularly attractive pecking stimulus. In one experiment, 72 chickens were exposed to be a sting stimulus. Instead white sting, blue-colored string was used. The number of pecks each chicken took at the blue string over a specified time interval was recorded. Summary statistics for the 72 chickens were x?=1.13 pecks, s= 2.21 pecks (Applied Animal Behavior Science, Oct. 2008).

a) (5 points) Estimate the population mean number of pecks made by chickens pecking at blue string using a 99% confidence interval.

b) (5 points) Previous research has shown that μ=7.5 pecks if chickens are exposed to white string. Conduct a test (at α=.01) to determine if the true mean number of pecks at blue string is less than μ=7.5 pecks.