There is a column of numbers. The first number is 105 and the second number is 85. Starting from the third number, each number is the average of the two numbers before it. Then the integer part of the number 2011 is______ ．

There is a column of numbers. The first number is 105 and the second number is 85. Starting from the third number, each number is the average of the two numbers before it. Then the integer part of the number 2011 is______ ．

The average of 105 and 85 is 95; the average of 85 and 95 is 90; the average of 95 and 90 is 92.5; the average of 90 and 92.5 is 91.25; the average of 92.5 and 91.25 is 91.875; the average of 91.25 and 91.875 is 91.5625 The integer part of the next number is 91, so the integer part of the 2011 number is 91

The average of five numbers is 30. If one of them is changed to 50, the average of five numbers is 25______ ．

(30-25) × 5 + 50 = 25 + 50 = 75, so the answer is: 75

It is known that the average number of 20 data is 20, and the average number of 15 data is 30, then the average number of the other 5 data is 20

20*20=400
15*30=450
400-450=-50
-50/5=-10

The average number of the four numbers is 50. If one of the four numbers is changed to 20, the average number of the four numbers becomes 30. What is the changed number?

（50-30）*4+20=100