To celebrate the May 4th Youth Day, a middle school held a calligraphy competition. After the competition, sort out the scores of the participating students and make a chart as follows: scores.

n = 1-0. 15-0. 15-0. 1 = 0.30。

So the answer is: 90, 0.30;

(2) The complete frequency distribution histogram is as follows:

(3) 200 people participated in the competition, 30 people scored between 60 and 70, 90 people scored between 70 and 80, and the median seat score fell between 70 and 80;

(4).x = 65×0. 15+75×0.45+85×0.30+90×0. 10 = 78.5，

So the average score of the contestants is about 78.5 points.