Answer:
c
Step-by-step explanation:
i choose (c) because that the answer
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
The correct answer is 3b-2=4
Hope this helps.
Answer:
1: 11√3 - 7√6
2: 11√3 - 7√6
3: -9
4:12
Step-by-step explanation:
To add radicals they need to have the same radical part for the first one we have
7√3- 4√6 + √48 - √54
We can simplify the last two into 4√3 and 3√6
So we have 7√3 - 4√6 + 4√3 - 3√6
adding similar radicals we get
11√3 - 7√6
For the second one we have 11√3 - 7√6
There's nothing we can do from here so keep that as your answer
This one is quite easy -3√9
square root of 9 is 3
so we have -3*3 which is -9
next is
4√9
same deal as the one before
3*4=12
