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 second degree polynomial with leading coefficient of -2 and root 4 with multiplicity of 2 is:

<h3>
How to write the polynomial?</h3>
A polynomial of degree N, with the N roots {x₁, ..., xₙ} and a leading coefficient a is written as:

Here we know that the degree is 2, the only root is 4 (with a multiplicity of 2, this is equivalent to say that we have two roots at x = 4) and a leading coefficient equal to -2.
Then this polynomial is equal to:

If you want to learn more about polynomials:
brainly.com/question/4142886
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Answer:
ujn uzun g ne bu bu http TV fy ve g CD ve de c TT vcxcxc TR TRT TT ttgrsxfgzfggfxvzgrstgygfdfdzvsdcvzdcgz TR
Answer:
91
Step-by-step explanation:
155-16s²
155- 16x2²
155- 16x4
155-64
91
Answer:
cos (theta) = √21/5
Step-by-step explanation:
sin (theta) = 2/5
(sin (theta))^2 = 4/25
4/25 + (cos (theta))^2 = 1
(cos (theta))^2 = 1 - 4/25 = 21/25
cos (theta) = √21/5