Which number is the additive inverse of -10 1/4

32 and 47.5%

Step-by-step explanation:

Given that X-scores on a psychology exam were normal

X:N(56,6)

Failing grade is 2 or more std deviations below the mean

Mean =56

2 std deviations =12

Mean-2 std dev =56-2(12)

=56-24

=32

Hence failing score cutoff is 32

I.e. if a student scores less than 32, he is deemed to have failed in the exam

Percentage of students failed = 100*P(X<32)

= P(Z<-2)

=100(0.475)

=47.5%

=