Answer:
Step-by-step explanation:
The area of an equilateral triangle with side length is equal to . Since the perimeter is 24 units and there are three equal sides to an equilateral triangle, each side is units.
Substituting in this value, we get:
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:
proportional/equal
Step-by-step explanation:
doesnt need
9514 1404 393
Answer:
D. y = ±√(25 -x²)
Step-by-step explanation:
Subtract x² and take the square root to solve for y.
x² +y² = 25 . . . . . . . given
y² = 25 -x² . . . . . . . . subtract x²
y = ±√(25 -x²) . . . . . take the square root