Male fiddler crabs solicit attention from the opposite sex by standing in front of their burrows and waving their claws at the females who walk by. If a female likes what she sees, she pays the male a brief visit in his burrow. If everything goes well and the crustacean chemistry clicks, she will stay a little longer and mate. In what may be a ploy to lessen the risk of spending the night alone, some of the males build elaborate mud domes over their burrows. Do the following data (215) suggest that a male’s time spent waving to females is influenced by whether his burrow has a dome? Answer the question by constructing and interpreting a 95% confidence interval for μX − μY. Use the value sp = 11.2.
% of Time Spent Waving to Females
Males with Domes, xi Males without Domes, yi 100.0 76.4
58.6…………………………84.2
93.5………………………..96.5
83.6………………………..88.8
84.1………………………..85.3
79.1
83.6