The lines intersect at (-1.8,-4.4)
<span>Suppose 2x + y = 15 -----eq 1
. x + 3y = 20 -----eq 2.
Multiplying eq (1) by 1 and (2) by 2 and subtracting the result
We have: 2x + y = 15 and 2x +6y =40.If we subtract, we have y - 6y = 15 - 40.
So we have -5y = -25. y is 5. Substiting into eq (1), we have 2x + 5 = 15. 2x = 15-5 =10 Hence X =5.Hence option B is the correct option.</span>
Answer:
x = 5
Step-by-step explanation:
5(2x-5) +10x = 75
10x -25 +10x = 75
20x - 25 = 75
20x = 100
x = 5
Answer:
68% of the sample can be expected to fall between 28 and 32 cm
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 = 30
Standard deviation = 2
What proportion of the sample can be expected to fall between 28 and 32 cm
28 = 30-2
28 is one standard deviation below the mean
32 = 30 + 2
32 is one standard deviation above the mean
By the Empirical Rule, 68% of the sample can be expected to fall between 28 and 32 cm
