System of Linear Equations entered :
[1] y - 2x/3 = -1
[2] y + x = 4
// To remove fractions, multiply equations by their respective LCD
Multiply equation [1] by 3
// Equations now take the shape:
[1] 3y - 2x = -3
[2] y + x = 4
Graphic Representation of the Equations :
-2x + 3y = -3 x + y = 4
Solve by Substitution :
// Solve equation [2] for the variable x
[2] x = -y + 4
// Plug this in for variable x in equation [1]
[1] 3y - 2•(-y +4) = -3
[1] 5y = 5
// Solve equation [1] for the variable y
[1] 5y = 5
[1] y = 1
// By now we know this much :
y = 1
x = -y+4
// Use the y value to solve for x
x = -(1)+4 = 3
I hope this help you
The <em><u>correct answer</u></em> is:
We can conclude that 68% of the scores were between 55 and 85; 95% of the scores were between 40 and 100; and 99.7% of the scores were between 25 and 100.
Explanation:
The empirical rule tells us that in a normal curve, 68% of data lie within 1 standard deviation of the mean; 95% of data lie within 2 standard deviations of the mean; and 99.7% of data lie within 3 standard deviations of the mean.
The mean is 70 and the standard deviation is 15. This means 1 standard deviation below the mean is 70-15 = 55 and one standard deviation above the mean is 70+15 = 85. 68% of data will fall between these two scores.
2 standard deviations below the mean is 70-15(2) = 40 and two standard deviations above the mean is 70+15(2) = 100. 95% of data will fall between these two scores.
3 standard deviations below the mean is 70-15(3) = 25 and three standard deviations above the mean is 70+15(3) = 115. However, a student cannot score above 100%; this means 99.7% of data fall between 25 and 100.
Answer:
on the seventh day
Step-by-step explanation:
hope this helps
I will send you a hopefully helpful link. https://www.ncdc.noaa.gov/sotc/national/201403
