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
Decimal: 3.5
350 divided by 100 = 3.5
Percentage: 350%
Move the decimal 2 times to the right
3.5 -> 350
Add a percent sign
Once upon a time there was a guy named Jeff. he went to a new school where he moved. so he was all by himself with no friends at all.. so then he met this guy named Zac so it was 1+1=2. and they were bff so they lived happily ever after together being bffs
To find the unit price of each item you want to divide:
Fresh water:
$1.76 / 16 = $0.11
Spring water:
$2.40 / 20 = $0.12
So the statement that is true is B) Fresh water has a lower unit price of $0.11/ounce.
Hope this Helps!!
