Answer:
hkkr
need school the long said
Answer:
99.7%
Step-by-step explanation:
Bell shaped curve by empirical rule is that if the standard deviation from the mean (left to right) is 1 deviation then about 68% of the data is in that range if it’s 2 standard deviations away then it’s 95% and 3 deviations away is 99.7%
142-100=42=3(14)
100-58=42=3(14)
Therefore the data is three standard deviations from the mean and this there is 99.7% of the data in this range.
Answer:
15.75 or 63/4
Step-by-step explanation:
Answer:
16cm
Step-by-step explanation:
Let the breadth = x
The length exceeds = x + 7
The breadth increased = x + 3
Because it said the length decreased by 4 so, the length would be:
x + 7 - 4 = x + 3
Original area:
We learn that:
area = length * breadth
x*(x+7) = (x+3)*(x+3)
x^2 + 7x = (x+3)^2
x^2 + 7x = x^2 + 6x + 9 (We also learn that (a+b)^2 = a^2 + 2ab + b^2
x^2 - x^2 + 7x - 6x = 9
x = 9 (so the breadth = 9)
The length = x + 7 = 9+7 = 16(cm)
Hope this help you :3
X = amount of 50% solution
y = total amount after mixing
Note that the amount of alcohol in the 20% solution is 80 (0.2) = 16 oz.
We have 2 unknowns, so we need 2 equations:
first, we can write the equation for the total volume:
y = x + 80
next, apply the percentages to get an equation for the amount of alcohol:
0.4 y = 0.5 x + 16
Finally, solve the pair of equations (in this case, by substitution of the 1st into the second:
0.4 (x + 80) = 0.5x + 16
0.4 x + 32 = 0.5X + 16
rearrange and combine like terms:
0.1x = 16
x = 160
from the 1st equation:
y = 160 + 80 = 240
