Answer:
So then the correct answer would be:
B) .9996
Step-by-step explanation:
The exact way to solve this problem is using the binomial distribution, assuming that our random variable of interest is "number of students living in apartments" represented by X and 
And we want this probability:
![P(200 \leq X \leq 400) [tex]In order to find this probability we can use the foloowing excel code:"=BINOM.DIST(400,600,0.4,TRUE)-BINOM.DIST(199,600,0.4,TRUE)"And we got:[tex] P(200 \leq X \leq 400) =0.999675[tex]But for this case the problem says that we need to approximate, so then we can use the normal approximation to the normal distribution. We need to check the conditions in order to use the normal approximation. [tex]np=600*0.4=240\geq 10](https://tex.z-dn.net/?f=%20P%28200%20%5Cleq%20X%20%5Cleq%20400%29%20%5Btex%5D%3C%2Fp%3E%3Cp%3EIn%20order%20to%20find%20this%20probability%20we%20can%20use%20the%20foloowing%20excel%20code%3A%3C%2Fp%3E%3Cp%3E%22%3DBINOM.DIST%28400%2C600%2C0.4%2CTRUE%29-BINOM.DIST%28199%2C600%2C0.4%2CTRUE%29%22%3C%2Fp%3E%3Cp%3EAnd%20we%20got%3A%3C%2Fp%3E%3Cp%3E%5Btex%5D%20P%28200%20%5Cleq%20X%20%5Cleq%20400%29%20%3D0.999675%5Btex%5D%3C%2Fp%3E%3Cp%3EBut%20for%20this%20case%20the%20problem%20says%20that%20we%20need%20to%20approximate%2C%20so%20then%20we%20can%20use%20the%20normal%20approximation%20to%20the%20normal%20distribution.%20%3C%2Fp%3E%3Cp%3EWe%20need%20to%20check%20the%20conditions%20in%20order%20to%20use%20the%20normal%20approximation.%0A%3C%2Fp%3E%3Cp%3E%5Btex%5Dnp%3D600%2A0.4%3D240%5Cgeq%2010)
So we see that we satisfy the conditions and then we can apply the approximation.
If we appply the approximation the new mean and standard deviation are:
And then 
And we are interested on the following probability:
So then the correct answer would be:
B) .9996
Answer:
Options (3), (4) and (5)
Step-by-step explanation:
1). a² - 9a + 7ab + 63b
= a(a - 9) + 7b(a + 9)
Now we can not solve this problem further.
Therefore, can't be factored by grouping.
2). 3a + 4ab - b - 12
= a(3 + 4b) - 1(b - 12)
We can't solve it further.
Therefore, can't be factored by grouping.
3). ab + 6b - 2a - 12
= b(a + 6) - 2(a + 6)
= (b - 2)(a + 6)
We can be factored this expression by grouping.
4). x³ + 9x²+ 7x + 63
= x²(x + 9) + 7(x + 9)
= (x² + 7)(x + 9)
Therefore, the given expression can be factored by grouping.
5). ay² + a - y² - 1
= a(y² + 1) - 1(y² + 1)
= (a - 1)(y² + 1)
This expression can be factored by the grouping method.
Options (3), (4) and (5) are the correct answers.
Answer:
Fraction 1/6. Decimal .6 or 1.6
Step-by-step explanation:
Answer:
YES SIR!
Step-by-step explanation:
its
x=4 y=6
x= 6 y=9
1/2.
divide everything by 9.
