Question

To examine the potential effects on the transmission of dengue, Bian et al. (2010) infected mosquitoes from both the WB1 (laboratory created) strain and the original wild strain with dengue. Fourteen days later, the mosquitoes were allowed to feed on an artificial food solution for 90 minute. Viral titers in the food solution were then measured (in plague feeding units [pfu] per ml. The results are given below. Mosquitoes were tested in groups, and so each data value is an average for the group, measured in pfu/ml. The data have already been log-transformed using log(Y+1), to better visualize the differences.

WB1:	Wild:
8	11.3
5.9	10.8
4.4	9.4
4.4	6.5
2.4	6.3
0	5.9
0	4.7
0	4.2

Rank the data and use the Mann-Whitney U-test to solve for U_{1. Round your answer to 1 decimal place}

Answer 1