What grade is this for by the way?
Answer:
Mean is 0.6.
Standard deviation is 0.059
Step-by-step explanation:
The first step is finding the sample proportion p.
Suppose Maria, a researcher, takes a random sample of 70 Americans and finds that 42 are over the age of 20.
This means that ![p = \frac{42}{70} = 0.6](https://tex.z-dn.net/?f=p%20%3D%20%5Cfrac%7B42%7D%7B70%7D%20%3D%200.6)
What are the mean and standard deviation of the sampling distribution of p?
Mean:
The mean of a proportion is the same as the proportion. So the mean is 0.6
Standard deviation:
Proportion p in a sample of size n. The standard deviation is:
![s = \sqrt{\frac{p(1-p)}{n}}](https://tex.z-dn.net/?f=s%20%3D%20%5Csqrt%7B%5Cfrac%7Bp%281-p%29%7D%7Bn%7D%7D)
Sample size 70, so:
![s = \sqrt{\frac{0.6*0.4}{70}} = 0.059](https://tex.z-dn.net/?f=s%20%3D%20%5Csqrt%7B%5Cfrac%7B0.6%2A0.4%7D%7B70%7D%7D%20%3D%200.059)
Answer:
4 in, 8 in, 15 in
Step-by-step explanation:
If x, y, z are the three pieces, then:
x + y + z = 27
y = 2x
z = 3 + 3x
Substitute the second and third equations into the first.
x + 2x + 3 + 3x = 27
6x + 3 = 27
6x = 24
x = 4
y = 8
z = 15
Answer:
64
Step-by-step explanation:
I'm assuming this is what the question means, so basically every 4/125 discs are defective, and 125 fits into 2000, 16 times so you multiply 4/125*16/16 so you get 64/2000.hope this helps
Answer:
180
Step-by-step explanation:
According to the table, the relationship between the x and the y value is 20, (4*20 = 80) (5*20 = 100) etc.
The graph with the points has a relationship of 35 (2*35 = 70) (4*35 = 140) etc. Therefore, you can figure out what y-value 12 would have for the table and the graph by multiplying 12 by 20 or 35 respectively.
12*20 = 240
12*35 = 420
420-240 = 180