<image>The school uses the geography test scores of students in Class 1 as a sample, categorizing them into four grades: A, B, C, and D, and creates two statistical charts based on the results. Based on the information in the charts, fill in the blanks:


(1) The percentage of students in Grade D is _______;
(2) The central angle of the sector representing Grade C in the pie chart is _______;
(3) The median of the geography test scores for this class falls within Grade _______;
(4) If the school has a total of 1500 students, estimate the number of students with Grade A in geography to be about _______.