<image>After sampling and statistical analysis of the ages of 800 volunteers in a city's "Four Cities Joint Creation" activity, a frequency distribution histogram was obtained (see figure). However, the data for the age group [25,30) was inadvertently lost. According to this figure:  (1) The height of the small rectangle corresponding to the age group [25,30) is ________. (2) Based on this, it is estimated that the number of volunteers aged [25,35) in the city's "Four Cities Joint Creation" activity is _________.