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:
Which is the smallest number which leaves remainder 8 and 12 when divided by 28 and 32 respectively? 204.
Step-by-step explanation:
Have a great summer.
Answer:
A, B, E area ll less than 0
Step-by-step explanation:
They are all negative numbers.
Answer:
The answer is 5
Step-by-step explanation:
Hope it helps <3 c:
Step-by-step explanation:
let's look at the last line :
x³ + 8x - 3 = Ax³ +5Ax + Bx² + 5B + Cx + D
since we find A, B, C, and D by simply comparing the factors of the various terms in x (or constants) in both sides of the equation, we need to combine a few terms on the right hand side (so that we have one term per x exponent grade).
x³ + 8x - 3 = Ax³ + (5A + C)x + Bx² + (5B + D)
by comparing now both sides, to make both sides truly equal, the factors have to be equal.
A = 1 (the same as for x³ on the left hand side).
B = 0 (a we have no x² on the left side).
5A + C = 8 (a 8 is the factor of x in the left side).
5×1 + C = 8
5 + C = 8
C = 3
5B + D = -3 (as the constant term is -3 on the left side).
5×0 + D = -3
D = -3
so, the 4th answer option is correct.