Answer:
The minimum sample size needed is
. If n is a decimal number, it is rounded up to the next integer.
is the standard deviation of the population.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Z-table as such z has a p-value of
.
That is z with a pvalue of
, so Z = 1.645.
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
How large a sample must she select if she desires to be 90% confident that her estimate is within 4 ounces of the true mean?
A sample of n is needed, and n is found when M = 4. So






The minimum sample size needed is
. If n is a decimal number, it is rounded up to the next integer.
is the standard deviation of the population.
The solution for the x-value in this set is -7≤x
I wanna say 10 or ether -10 since if it was subtracted from 2 then it would equal -8
Answer:
Part 1) 
Part 2) 
Part 3) 
Step-by-step explanation:
Part 1) Find AC
we know that
In the right triangle ABC of the figure
Applying the Pythagorean Theorem

substitute the given values


Part 2) Find the measure of angle A
we know that
In the right triangle ABC
----> by TOA (opposite side divided by the adjacent side)
substitute the values

using a calculator

Part 3) Find the measure of angle C
we know that
In the right triangle ABC
----> by complementary angles
substitute the given value

