Answer:
any score that lies between 88.8 and 97.2 is within one std. dev. of the mean
Step-by-step explanation:
One std. dev. above the mean would be 93 + 4.2, or 97.2. One std. dev. below the mean would be 93 - 4.2, or 88.8.
So: any score that lies between 88.8 and 97.2 is within one std. dev. of the mean.
Step-by-step explanation:
4x + 2y = 10 --------(1)
2x + 3y = 33 -----------(2)
Multiply 2 with eq. (1) and 4 with eq. (2)
8x + 4y = 20 ____________(3)
8x + 12y = 132 ______(4)
Subtracting (3) from (4),
8x + 4y = 20
- 8x -12y = -132
----------------------
0 -8y = -112
y = 112/8
y = 4 is the answer.
Putting the vakue of y in eq. (2),
2x + 12 = 33
2x = 33-12
2x = 21
x = 21/2 is the answer.
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