(22.) You have the temperature changes listed correctly, you just messed up the math.
-7 + 9 - 6 - 4
-17 + 9 = - 8°F
(23.) There are 76 fewer parks in Arizona which has 29.
76 + 29 = 105 parks in California
(24.) For the average, add up all values and divide by the number of them
-6 + 0 + 2 + -9 + -5 + 10 + 1
-20 + 13 = - 7
there are 7 numbers
average = - 7/7 = -1°F