Answer:
Step-by-step explanation:
let x and y be length and width of rectangle.
Perimeter=2(x+y)
area=xy
2(x+y)=1/2 xy
4(x+y)=xy
4x+4y=xy
x y-4y=4 x
y(x-4)=4 x

Answer:
b. II only
Step-by-step explanation:
Hello!
I. The populations from which the samples are drawn must be at least 10 times greater than the samples.
Incorrect, when sampling the size of the population only matters if it is a finite population (For example if you are studying an endangered species whose number is known, you have to take that into account when calculating the sample size) for infinite populations there are no restrictions about the sample size or its proportion in relation with it. As long as the sample is representative of the population to allow you to infer about it.
II. How you compute the standard error depends on whether you are constructing a confidence interval or performing a significance test.
Correct, the standard deviation for the sample proportion is
and for two proportions
, as you see the standard deviation contains the population proportion.
When doing an hypothesis test for one population, you state the possible number of the proportion in the hypothesis and therefore you can use it to calculate the standard deviation.
When making an hypothesis test for the difference between two population proportions the standard deviation is computed with a pooled sample proportion. 
When estimating the population proportion/s, since there is no information about the population value/s (If it was the estimation would be pointless) the standard deviation is also estimated and you calculate it using the information of the sample proportion:
One population:
Two populations: 
III. When you are doing inference for proportions, you use z-procedures because of the sampling distribution of pˆis normal.
Incorrect, the distribution of the sampling proportions is binomial, you can approximate it to normal by applying the Central Limit Theorem.
I hope it helps!
Answer:
b x h / 2
Step-by-step explanation:
Ok well i had this problem on a quiz haha i forgot wha i did exacally but i can solve it. so where you start is you find what the table will equal at 12 and thats 360 so you got that right by multiplying 5 times 30 and getting 150, then you added 150 to 210. after that yo will want to find out what the graph will equal so you would want to 8 from 12 and you would get 4.
If you see the graph goes up by 2s so you need to see how much it goes up in 2 times and split that in half. so you find that it goes up 110 in 2 times so you split that in half and get 55. so then you will multiply 55 (how many times it goes up once) by 4 (how many times you will get to be to 12) When you multiply that you will get 220.
So your chart equals 360 and your graph equals 220. If you subtract both of those you get 120. so that would be your answer