Answer:
52
Step-by-step explanation:
Given that :
Mean (m) = 78
Standard deviation (s) = 13
Score that is 2 standard deviations below the mean
Using the relation :
Zscore = (x - m) / s
2 standard deviations below the mean means a Zscore of - 2
Hence,
-2 = (x - 78) / 13
Cross multiply
-2 * 13 = x - 78
-26 = x - 78
x = - 26 + 78
x = 52
Score which is 2 standard deviations below the mean is 52
Answer:
5
Step-by-step explanation:
3x -12 = -36
-36 ÷ -3 = 12
-7 + 12 = 5
1 meter :12 cm
1 cubic meter = 1 x 1 x 1 : 12 x 12 x 12 = 1,728 cubic cm.
Answer:
4=x y=325
Step-by-step explanation:
60x + 20 = 65x
group the variables
20=5x
because you subtracted 60x from both
4=x
because you divided 5 from both
now substitute 5 for x
65×5 is 325
y=325
Answer:
Multiply 9 by 6
Step-by-step explanation:
7:9 is the ratio
We multiply the first term by 6.
What we do to one side, we do to the other
7*6=42
9*6 = 54
That way we keep the ratio in the same proportion
42:54
