If the mean score is 55% and the s.d. is 15%, then a test score of at least
55% + 1.5 × 15% = 77.5%
falls in the A range.
The next cutoff score is 0.5 s.d. from the mean, which is
55% + 0.5 × 15% = 62.5%
so any test score between 62.5% and 77.5% is in the B range.
The next cutoff is
55% - 0.5 × 15% = 47.5%
so a score between 47.5% and 62.5% gets a C.
The lower limit of the next range is
55% - 1.5 × 15% = 32.5%
so 32.5% - 47.5% gets a D.
Anything lower than 32.5% is an F.
Answer:
a) 9
b) -3
Step-by-step explanation:
a)
|9+x|=2x
9 + x = 2x
- x -x
---------------
9 = x
b)
|x+6|=2x+9
x +6 = 2x +9
-x -x
6 = x + 9
-9 -9
--------------
-3 = x
Answer:
a =6
b=4
c=2
step-by-step explanation:
= 
= 
= 
Answer:
D
Step-by-step explanation:
Congruent angles are identical in number of degrees.
