Answer:
0.0326 = 3.26% probability that she is a student.
Step-by-step explanation:
Conditional Probability
We use the conditional probability formula to solve this question. It is

In which
P(B|A) is the probability of event B happening, given that A happened.
is the probability of both A and B happening.
P(A) is the probability of A happening.
In this question:
Event A: Woman developer
Event B: Student
Probability that the developer is a woman:
7.4% of 25.8%(students).
76.4% of 100 - 25.8 = 74.2%(not students). So

Student and woman developer.
7.4% of 25.8%(students), so

If we encounter a woman developer, what is the probability that she is a student

0.0326 = 3.26% probability that she is a student.
Answer:
We are 95% confident that the true proportion of TV audience is between 65.15% and 65.85%
Step-by-step explanation:
-From the given information,
.
-We calculate the confidence interval using this value at 95% confidence level:
![CI=\hat p\pm z \sqrt{\frac{\hat p(1-\hat p)}{n}}\\\\\\=0.65\pm 1.96\times \sqrt{\frac{0.65\times 0.35}{12000}}\\\\\\=0.65\pm 0.0085\\\\\\=[0.6415,0.6585]](https://tex.z-dn.net/?f=CI%3D%5Chat%20p%5Cpm%20z%20%5Csqrt%7B%5Cfrac%7B%5Chat%20p%281-%5Chat%20p%29%7D%7Bn%7D%7D%5C%5C%5C%5C%5C%5C%3D0.65%5Cpm%201.96%5Ctimes%20%5Csqrt%7B%5Cfrac%7B0.65%5Ctimes%200.35%7D%7B12000%7D%7D%5C%5C%5C%5C%5C%5C%3D0.65%5Cpm%200.0085%5C%5C%5C%5C%5C%5C%3D%5B0.6415%2C0.6585%5D)
So, the 95% confidence interval is (0.6515,0.6585).
Hence, we are 95% confident that the true proportion of TV audience is between 65.15% and 65.85%.
Answer:
Step-by-step explanation:
11=4(8)+b
11=32+b
-21=b
y=4x-21
i think
Answer:

The world population at the beginning of 2019 will be of 7.45 billion people.
Step-by-step explanation:
The world population can be modeled by the following equation.

In which Q(t) is the population in t years after 1980, in billions, Q(0) is the initial population and r is the growth rate.
The world population at the beginning of 1980 was 4.5 billion. Assuming that the population continued to grow at the rate of approximately 1.3%/year.
This means that 
So


What will the world population be at the beginning of 2019 ?
2019 - 1980 = 39. So this is Q(39).


The world population at the beginning of 2019 will be of 7.45 billion people.