Answer:
x=-6
Step-by-step explanation:
3x+2=-40-4x
add 4x to both sides to get
3x+4x+2=-40
now subrtact 2 from both sides
3x+4x=-40-2
combine like terms
7x=-42
divide -42/7
x=-6
Row A is incorrect, because 3 times 4 is 12 and 12 + 5 = 17 not 20.
Answer:
2.5% of IQ scores are no more than 65
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 95
Standard deviation = 15
Using the empirical rule, what percentage of IQ scores are no more than 65?
65 = 95 - 2*15
So 65 is two standard deviations below the mean.
By the Empirical Rule, 95% of the measures are within 2 standard deviation of the mean. Of those 5% which are not, 2.5% are more than 2 standard deviations above the mean and 2.5% are more than 2 standard deviations below the mean.
So 2.5% of IQ scores are no more than 65
Answer:
14 cm.
Step-by-step explanation:
Let the radius of the circle = r cm.
Then circumference of circle = 2 π r.
Since circumference exceeds the radius by 74 cm
Therefore, according to the question,
![\sf \:2 π r = r+ 74](https://tex.z-dn.net/?f=%5Csf%20%5C%3A2%20%CF%80%20r%20%3D%20r%2B%2074%20)
![\sf \: = > 2 \times \frac{22}{7} \times r = r \: + 74](https://tex.z-dn.net/?f=%5Csf%20%5C%3A%20%3D%20%20%20%3E%202%20%5Ctimes%20%20%5Cfrac%7B22%7D%7B7%7D%20%20%5Ctimes%20r%20%3D%20%20r%20%5C%3A%20%20%2B%2074)
![\sf \: = > \frac{44r}{7} -r = 74](https://tex.z-dn.net/?f=%20%5Csf%20%5C%3A%20%3D%20%20%3E%20%20%5Cfrac%7B44r%7D%7B7%7D%20%20-r%20%20%3D%2074)
![\sf \: = > \frac{44r - 7r}{7} = 74](https://tex.z-dn.net/?f=%5Csf%20%5C%3A%20%20%3D%20%20%3E%20%5Cfrac%7B44r%20-%207r%7D%7B7%7D%20%20%3D%2074)
![\sf \: = > \frac{37r}{7} = 74](https://tex.z-dn.net/?f=%20%5Csf%20%5C%3A%20%3D%20%20%3E%20%20%5Cfrac%7B37r%7D%7B7%7D%20%20%3D%2074)
![\sf \: = > r = \frac{7 \times 74}{37}](https://tex.z-dn.net/?f=%5Csf%20%5C%3A%20%3D%20%20%3E%20r%20%3D%20%20%5Cfrac%7B7%20%5Ctimes%2074%7D%7B37%7D%20)
![\sf \: = > r = 14](https://tex.z-dn.net/?f=%5Csf%20%5C%3A%20%3D%20%20%3E%20%20r%20%3D%2014)
- Hence, the radius of the circle is 14 cm.
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