Data set info: Students and faculty at Cornell College in Mount Vernon, Iowa, collected the data over many years at the hawk blind at Lake MacBride near Iowa City, Iowa. The data set that we are analyzing here is a subset of the original data set. Data were collected on random samples of two different species of hawks: Red-tailed and Sharp-shinned hawks. The variable "Tail" gives a measurement (in mm) related to the length of the tail (invented at the MacBride Raptor Center).

1. State the population of interest.

2. Identify the explanatory variable (this will be a categorical variable).

3. Identify the response variable and give its units.

4. Explain whether or not we satisfy the conditions for a valid t-test. Briefly provide justification for each condition that is satisfied and for those that aren't indicate that the condition must be assumed in order to perform the test.