<image>Statistics of the high jump test results for some eighth-grade students are presented in the following frequency distribution histogram:
(1) What is the total number of participants in the test?
(2) What is the class interval?
(3) Which group has the highest frequency? State the group's median value and boundary values.
(4) How many students achieved a high jump result of more than 1.29 meters? What percentage of the total number of participants does this represent?