Witch expression would be easier to simply if you used commutative property to change the order of the numbers A. 1/7 + (-1) + 2/7
B. 120 + 80 + (-65)
C. 40+ 10 + (-12)
D. -15 + (-25) + 43
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Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?