Because ABCD is a rectangle, the length of CD is 12 cm.
We need to determine the length of DE. If we can do that, then the sum of the lengths of CD and DE represents the unknown: the length of CE.
To find the length of CE, we have to "solve" the upper triangle.
Here's an outline of what to do:
1. Show that BC=AD and find the length.
2. Note that angle CAD is 60 degrees. Why?
3. Note that angle EAD is 30 degrees. Why?
4. Find the length of ED
5. Add ED and DC, that is, ED + 12 cm. This is your answer.
Please ask questions if need be.
Answer: 554
Step-by-step explanation:
If prior population proportion is known, then the formula to find the sample size is given by :-

As per given description, we have
p= 0.1
E=0.025
Critical z-value for 95% confidence : 
Then,

Hence, the minimum sample size required = 554.
What answer are you looking for percents,fraction form, etc ?
Answer:
x = -5 y = -3
Step-by-step explanation:
-3x + 2y = 9
multiply the 2nd equation by 3 to set it up for elimination
3(x - 3y)= 3(4)
3x-9y = 12
so now combine both to add
-3x + 2y = 9
3x - 9y = 12
Adding both gives you
-7y = 21
divide both by -7 and you get
y = -3
and you substitute y back into equation to get x
x - 3 (-3) = 4 gives you
x + 9 = 4
x = 4 - 9
x = -5
384. 25 is the correct answer.