Answer:4
Step-by-step explanation:
Let a denotes the no of odd ball selected and b denotes the no of even ball selected
then ![X=3 a+4 b](https://tex.z-dn.net/?f=X%3D3%20a%2B4%20b)
for ![a=0,b=3, X=12](https://tex.z-dn.net/?f=a%3D0%2Cb%3D3%2C%20X%3D12)
for ![a=1,b=2, X=11](https://tex.z-dn.net/?f=a%3D1%2Cb%3D2%2C%20X%3D11)
for ![a=2,b=1, X=10](https://tex.z-dn.net/?f=a%3D2%2Cb%3D1%2C%20X%3D10)
for ![a=3,b=0, X=9](https://tex.z-dn.net/?f=a%3D3%2Cb%3D0%2C%20X%3D9)
thus X can take 4 values i.e. 9,10,11 and 12
![P(X=9)\ i.e. 3\ odd\ balls\ and\ 0\ even\ balls=\frac{^{14}C_{3}}{^{28}C_3}=\frac{1}{9}](https://tex.z-dn.net/?f=P%28X%3D9%29%5C%20i.e.%203%5C%20odd%5C%20balls%5C%20and%5C%200%5C%20even%5C%20balls%3D%5Cfrac%7B%5E%7B14%7DC_%7B3%7D%7D%7B%5E%7B28%7DC_3%7D%3D%5Cfrac%7B1%7D%7B9%7D)
![P(X=10)\ i.e. 2\ odd\ balls\ and\ 1\ even\ balls=\frac{^{14}C_{2}\times ^{14}C_1}{^{28}C_3}=\frac{7}{18}](https://tex.z-dn.net/?f=P%28X%3D10%29%5C%20i.e.%202%5C%20odd%5C%20balls%5C%20and%5C%201%5C%20even%5C%20balls%3D%5Cfrac%7B%5E%7B14%7DC_%7B2%7D%5Ctimes%20%5E%7B14%7DC_1%7D%7B%5E%7B28%7DC_3%7D%3D%5Cfrac%7B7%7D%7B18%7D)
![P(X=11)\ i.e. 1\ odd\ balls\ and\ 2\ even\ balls=\frac{^{14}C_{1}\times ^{14}C_2}{^{28}C_3}=\frac{7}{18}](https://tex.z-dn.net/?f=P%28X%3D11%29%5C%20i.e.%201%5C%20odd%5C%20balls%5C%20and%5C%202%5C%20even%5C%20balls%3D%5Cfrac%7B%5E%7B14%7DC_%7B1%7D%5Ctimes%20%5E%7B14%7DC_2%7D%7B%5E%7B28%7DC_3%7D%3D%5Cfrac%7B7%7D%7B18%7D)
![P(X=12)\ i.e. 0\ odd\ balls\ and\ 3\ even\ balls=\frac{^{14}C_{3}}{^{28}C_3}=\frac{1}{9}](https://tex.z-dn.net/?f=P%28X%3D12%29%5C%20i.e.%200%5C%20odd%5C%20balls%5C%20and%5C%203%5C%20even%5C%20balls%3D%5Cfrac%7B%5E%7B14%7DC_%7B3%7D%7D%7B%5E%7B28%7DC_3%7D%3D%5Cfrac%7B1%7D%7B9%7D)
Answer:
31 cm
Step-by-step explanation:
The area (A) of a trapezium is calculated as
A =
h (a + b)
where h is the height and a, b the bases
Here A = 162, h = 6 and a = 23 , then
× 6 (23 + b) = 162
3(23 + b) = 162 ( divide both sides by 3 )
23 + b = 54 ( subtract 23 from both sides )
b = 31
The other base is 31 cm
Answer:
0.8% or 80%
Step-by-step explanation:
24/30 is equivalent to 80/100
80/100 as a decimal is 80%
hope this helps :3
if it did pls mark brainliest
Let x and y equal our two numbers, then add them and set them equal to 27
x+y=27
Pick a variable to represent your larger number, then make an equation for it
y=2x+6
Substitute your equation for that variable back into the original equation so you get everything in terms of one variable.
x+2x+6=27
Solve!
3x+6=27
3x=21
x=7
Plug x back into the equation:
7+y=21
y=14
Answer:
range is between 294.32 and 227.68 expect the middle 95% of most pregnancies
Step-by-step explanation:
Given data
mean μ = 261 days
standard deviation SD = 17 days
most pregnancies = 95%
to find out
In what range expect to find the middle 95% of most pregnancies
solution
we have Z value for 95% is 1.96
so Confidence interval = mean +/- 1.96×SD
put vale
Confidence interval = 261 +/- 1.96(17)
Confidence interval = 294.32 and 227.68
range is between 294.32 and 227.68 expect the middle 95% of most pregnancies