Wah..I need to ask my bro to answer this.. Brb
Answer:
Part 1) 
Part 2) 
Step-by-step explanation:
Part 1) Find the value of x
we know that
Triangles CDF and FDE are similar
therefore
The ratio of its corresponding sides is proportional and its corresponding angles are congruent
so


Part 2) Find the length of DE

substitute the value of x

That literally means the numbers '5' and '12' written like this: 5 + 12
represent the sum of 5 and 12, which is the same as 5 + 12 (because the sum is when all the numbers are added up).
So it's saying 5 + 12 equals to 17.
Do you get it?
Complete Question
A magazine provided results from a poll of 500 adults who were asked to identify their favorite pie. Among the 500 respondents, 12 % chose chocolate pie, and the margin of error was given as plus or minus 5 percentage points.What values do
, n, E, and p represent? If the confidence level is 90%, what is the value of
?
Answer:
a
is the sample proportion
is the sample size is 
is the margin of error is 
represents the proportion of those that did not chose chocolate pie i.e 
b

Step-by-step explanation:
Here
is the sample proportion
is the sample size is 
represents the proportion of those that did not chose chocolate pie i.e



is the margin of error is 
Generally
is the level of significance and it value is mathematically evaluated as

Where
is the confidence level which is given in this question as 
So


the height:

(with g being the gravitational acceleration)