The sample proportion has an approximately normal distribution, with the mean being the population mean and the standard deviation (i.e. the standard error of the sampling proportion) equal to
SE = sqrt(p*q/n) where p is the population proportion q is 1-p, and n is the sample size.
<span>(Typically, for a confkdence interval, the sample proportion and its complement are substituted for p and q.) </span>
The margin of error will be Zc*SE, where Zc is the critical value of Z for the level of confidence required. The confidence interval, then, will be the sample proportion, plus or minus the margin of error.
For a 90% confidence interval, Zc is 1.645.
<span>So the margin of error is 1.645 * sqrt(.9*.1/400), roughly .025. So your confidence interval would be around [.875, .925]
The best and most correct answer among the choices provided by your question is the second choice or letter C which is 3%.
I hope my answer has come to your help. Thank you for posting your question here in Brainly.</span>
3.9
Hope that helps
You can use the app math.way also
Answer:
C (-2,1)
Step-by-step explanation:
−2x − y = 3 (1)
−9x − y = 17 (2)
(1) y = -2x - 3
(2) y = -9x - 17
-2x - 3 = -9x - 17
7x = -14
x = -2
y = -2(-2) - 3
y = 4 - 3
y = 1
Amount of purchase that Steve made = $40
Percentage of tax that Steve needs to pay = 10%
Then
Amount of tax that Steve needs to pay for the purchase = (10/100) * 40
= 1 * 4 dollars
= 4 dollars
Then
The total amount including tax
that Steve needs to pay for the purchase = (40 + 4) dollars
= 44 dollars
So the dollar amount of tax that Steve had to pay is $4 and
the total amount that Steve had to pay was $44.
Keywords:
<em>System of equations, variables, hardcover version, paperback version, books
</em>
For this case we must construct a system of two equations with two variables. Let "h" be the number of hardcover version books, and let "p" be the number of paperback version books. If the hardcover version of a book weighs 7 ounces and the paperback version weighs 5 ounces, to reach a total of 249 ounces we have:
(1)
On the other hand, if there are Forty-five copies of the book then:
(2)
If from (2) we clear the number of books paperback version we have:
As each paperback version book weighs 5 ounces, to obtain the total weight of the paperback version books, represented by "x" in the table shown, we multiply
So, 
Answer:
Option D
