Answer:
n=10
Step-by-step explanation:
-2=-n+8
-n=-10
n=10
-5x•(2x^2+x+3) is the answer
Answer:
He must survey 123 adults.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the z-score that has a p-value of
.
The margin of error is:

Assume that a recent survey suggests that about 87% of adults have heard of the brand.
This means that 
90% confidence level
So
, z is the value of Z that has a p-value of
, so
.
How many adults must he survey in order to be 90% confident that his estimate is within five percentage points of the true population percentage?
This is n for which M = 0.05. So






Rounding up:
He must survey 123 adults.
If tan (x)+pi/6=0
thn
tan (x)=-pi/6
take atan of both sides
x=atan (-pi/6)
x= -0.4823 rad
= -27.636 deg