The results for each part are as follows:
- Probability that the sample mean rent is greater than \$2769: \\(\boxed{0.5801}\\)
- Probability that the sample mean rent is between \$2568 and \$2668: \\(\boxed{0.1118}\\)
- 55th percentile of the sample mean rent: \\(\boxed{2742.50}\\)