Answer: 0.1457
Step-by-step explanation:
Let p be the population proportion.
Given: The proportion of Americans who are afraid to fly is 0.10.
i.e. p= 0.10
Sample size : n= 1100
Sample proportion of Americans who are afraid to fly =
We assume that the population is normally distributed
Now, the probability that the sample proportion is more than 0.11:
![P(\hat{p}>0.11)=P(\dfrac{\hat{p}-p}{\sqrt{\dfrac{p(1-p)}{n}}}>\dfrac{0.11-0.10}{\sqrt{\dfrac{0.10(0.90)}{1100}}})\\\\=P(z>\dfrac{0.01}{0.0090453})\ \ \ [\because z=\dfrac{\hat{p}-p}{\sqrt{\dfrac{p(1-p)}{n}}} ]\\\\=P(z>1.1055)\\\\=1-P(z\leq1.055)\\\\=1-0.8543=0.1457\ \ \ [\text{using z-table}]](https://tex.z-dn.net/?f=P%28%5Chat%7Bp%7D%3E0.11%29%3DP%28%5Cdfrac%7B%5Chat%7Bp%7D-p%7D%7B%5Csqrt%7B%5Cdfrac%7Bp%281-p%29%7D%7Bn%7D%7D%7D%3E%5Cdfrac%7B0.11-0.10%7D%7B%5Csqrt%7B%5Cdfrac%7B0.10%280.90%29%7D%7B1100%7D%7D%7D%29%5C%5C%5C%5C%3DP%28z%3E%5Cdfrac%7B0.01%7D%7B0.0090453%7D%29%5C%20%5C%20%5C%20%5B%5Cbecause%20z%3D%5Cdfrac%7B%5Chat%7Bp%7D-p%7D%7B%5Csqrt%7B%5Cdfrac%7Bp%281-p%29%7D%7Bn%7D%7D%7D%20%5D%5C%5C%5C%5C%3DP%28z%3E1.1055%29%5C%5C%5C%5C%3D1-P%28z%5Cleq1.055%29%5C%5C%5C%5C%3D1-0.8543%3D0.1457%5C%20%5C%20%5C%20%5B%5Ctext%7Busing%20z-table%7D%5D)
Hence, the probability that the sample proportion is more than 0.11 = 0.1457
He buyed 240 cards because
20
x
12
-----
40
+
20
-------
240
the answer is C.12.1 units
The answer to your question would be 0.01
We need to find two numbers that multiply to 24 (last coefficient) and add to 10 (middle coefficient). Through trial and error, the two values are 6 and 4
6 + 4 = 10
6*4 = 24
So we can break up the 10ab into 6ab+4ab and then use factor by grouping
a^2 + 10ab + 24b^2
a^2 + 6ab + 4ab + 24b^2
(a^2+6ab) + (4ab+24b^2)
a(a+6b) + 4b(a+6b)
(a+4b)(a+6b)
Therefore, the original expression factors completely to (a+4b)(a+6b)
