The old mean was 51 now the mean is 42.33... (round that to 42) 51 - 42 = 9
It should be acute because if A and B are complementary then B and A added together should be 90 so 90-30=60 and 60 would be an acute angle
Positive: 690
Negative: -30
N/4 less than or equal to 5
Answer:

Step-by-step explanation:

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