Answer:
The 90% confidence interval for the true mean natural gas bill for homes in the 19808 zip code area in February is between $292.48 and $331.32
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 21 - 1 = 20
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 20 degrees of freedom(y-axis) and a confidence level of . So we have T = 1.7247
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 311.9 - 19.42 = $292.48
The upper end of the interval is the sample mean added to M. So it is 311.9 + 19.42 = $331.32
The 90% confidence interval for the true mean natural gas bill for homes in the 19808 zip code area in February is between $292.48 and $331.32
Answer:
Option (a) is correct.
is a perfect cube.
Step-by-step explanation:
Given : Some Monomial
We have to choose out of given monomial that is a perfect cube.
Perfect cubes are numbers that can be written as
So, consider , we know 1 can be written as
Thus, can be written as
Thus, Option (a) is correct.
The radius of the circle is given to be r = 14.5
Let the center be O. So OB is the radius = 14.5
We can draw a triangle as shown in the image below. We have a right angled triangle. We know the hypotenuse and the base, we need to find the perpendicular side. This can be done using the Pythagorean theorem.
So, we can write:
Thus, the measure of OA = 10.5
OB = OA + AB
14.5 = 10.5 + AB
⇒
AB = 4
I have to write here as well apparently, but have added answer as picture
4/5 ,8/10, 16/20,
You multiply both numbers with the same number.
For ex. 4×2=8 5×2=10 so we have 8/10