Answer:
119.2
Step-by-step explanation:
Given the following :
Mean (m) = 100 years
Standard deviation (sd) = 15 years
closest to the age of a Galápagos Islands giant tortoise at the 90th percentile of the
distribution?
Obtain the Zscore for 90th percentile (0.90) on the z table = 1.28
Zscore = (X - mean) / standard deviation
1.28 = (X - 100) / 15
1.28 × 15 = X - 100
19.2 = X - 100
19.2 + 100 = X
X = 119.2
The answer is -6x^2 + 7x, or answer choice A.
The correct answer is -3.6. Hope this helps!!
Answer:
x= 8 y= 1
Step-by-step explanation:
First, you identify your variables:
x= larger number
y= smaller number
Second, you find your equations:
x - y = 7
2x + 3y = 19
Third, (I used the substitution method) you make "y" by itself for the 1st equation.
y = x - 7
2x + 3y = 19
Then, you plug in the 1st equation for "y" in the 2nd equation
2x + 3(x - 7) = 19
Then, you distribute and simplify.
2x + 3x - 21 = 19
5x - 21 = 19
5x = 40
x = 8
Finally, you plug in the variable you found ( x ) into one of the equations and solve,
8 - y = 7
- y = -1
y = 1
