We need to find out how many adults must the brand manager survey in order to be 90% confident that his estimate is within five percentage points of the true population percentage.
From the given data we know that our confidence level is 90%. From Standard Normal Table we know that the critical level at 90% confidence level is 1.645. In other words, 
.
We also know that E=5% or E=0.05
Also, since, 
is not given, we will assume that =0.5. This is because, the formula that we use will have 
in the expression and that will be maximum only when =0.5. (For any other value of , we will get a value less than 0.25. For example if, is 0.4, then 
and thus, 
.).
We will now use the formula
We will now substitute all the data that we have and we will get
which can approximated to n=271.
So, the brand manager needs a sample size of 271
Answer:
x=3 is your answer
Step-by-step explanation:
Hope this helps :)
Answer:
x² + y² = 34
Formula:
- (x - h)² + (y - k)² = r² where (h, k) is the center
<u>Here find the radius using distance formula</u>: → origin : (0, 0)
<u>Thus the equation of circle</u>:
- (x - 0)² + (y - 0)² = (√34)²
Answer:
43.4
Step-by-step explanation:
You will need to use the phythagoream therom, which is a² + b² = c². Plug the values in for the variables to get 7² + b² = 44², (c would equal the hypothenuse because the hypothenuse is the longest side of the triangle.) Square the values to get 49 + b² = 1936. Subtract 49 from both sides to get b² = 1887, then take the square root of both sides to get b = 43.4 (rounded to the nearest tenth.)
I am really sorry if I'm wrong, but have a good day/night! :)
Answer
Step-by-step explanation:
First we gave a name to the side that is common for both triangles, can be Y for example.
Using trigonometric functions we can make a relationship between the two angles that we have and the magnitud of the side.
, Because sin(x)= op/hip
, Because con(x)=ad/hip
Having this equations, we can solve the system and find x
we equal Y and solve
Then we rationalize
Hope you like it!
