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:
3141.59
Step-by-step explanation:
Answer:
It is 432
Step-by-step explanation:
Answer:
Step-by-step explanation:
In the diagram below we have
ABCD is a parallelogram. K is the point on diagonal BD, such that
And AK meets BC at E
now in Δ AKD and Δ BKE
∠AKD =∠BKE ( vertically opposite angles are equal)
since BC ║ AD and BD is transversal
∠ADK = ∠KBE ( alternate interior angles are equal )
By angle angle (AA) similarity theorem
Δ ADK and Δ EBK are similar
so we have
( ABCD is parallelogram so AD=BC)
( BC= BE+EC)
( subtracting 1 from both side )
taking reciprocal both side
Answer:
20ft^2
Step-by-step explanation:
The length is currently three feet, if you add two feet to three that makes five feet. Five times four is twenty.
I hope this helps!