Answer:
n=206
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The population proportion have the following distribution
Solution to the problem
In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 99% of confidence, our significance level would be given by
and
. And the critical value would be given by:
The margin of error for the proportion interval is given by this formula:
(a)
And on this case we have that
, we can use as prior estimate of p 0.5, since we don't have any other info provided, and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
And replacing into equation (b) the values from part a we got:
And rounded up we have that n=206
Answer:
15
Step-by-step explanation:
just took the test. x=5 and the answer to the equation is 15
The linear equation that has a slope of -7 and crosses the x-axis at (3, 0) is:
y = -7x + 21
<h3>
How to find the linear equation?</h3>
A general linear equation is:
y = a*x +b
Where a is the slope and b is the y-intercept.
The slope must be equal to the limit found in part a, and you say that it is equal to -7, so the slope is -7. And for how is written the problem, I understand that it crosses the x-axis at x = 3.
Then we will have:
y = -7*x + b
Such that, when x = 3, y = 0, then:
0 = -7*3 + b
21 = b
Then the linear equation is y = -7x + 21
If you want to learn more about linear equations:
brainly.com/question/1884491
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Answer:
Add 7 to both sides
Step-by-step explanation:
You would need to add 7 to both sides to cancel out the 7 on the right side of the equation to get x one step closer to being by itself.
Then you would get 4x = -8.
Next divide by 4 on both sides to get x by itself so do the inverse operation of what 4 was doing to x.
x = -2