Answer:
The sample mean is
b.3.55
The margin of error is
0.32
Step-by-step explanation:
Deep explanation about a confidence interval
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 Ztable as such z has a pvalue of .
So it is z with a pvalue of , so
Now, find M as such
In which is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the mean subtracted by M. So it is 6.4 - 0.3944 = 6.01 hours.
The upper end of the interval is the mean added to M. So it is 6.4 + 0.3944 = 6.74 hours.
In this problem:
The deep explanation is not that important.
We just have to recognize that the interval has a lower end and an upper end. The distance from both the upper and the lower end to the mean is M. This means that the sample mean is the halfway point between the lower end and the upper end.
The margin of error is the distance of these two points(lower and upper end) to the mean.
In our interval
Lower end: 3.23
Upper end: 3.87
Sample mean
So the correct answer is:
b.3.55
The margin of error is
3.87 - 3.55 = 3.55 - 3.23 = 0.32
Answer:
4 feet
Step-by-step explanation:
see the attached figure with letter to better understand the problem
we know that
A board is half way up each ladder
so
point B is the midpoint segment AC and point F is the midpoint segment AG
Than means
AB=AC/2 -----> AB=10/2=5 units
BF is parallel to segment CG ----> by Triangle midpoint segment theorem
step 1
In the right triangle ABD
Find the length side AD
Applying Pythagorean Theorem
solve for AD
step 2
Find the length of segment DE (h)
Remember that
If two triangles are similar, then the ratio of its corresponding sides is proportional
In this problem
Triangles ABD and ACE are similar by AA Similarity Theorem
so
substitute the given values
----> by segment addition postulate
substitute
solve for DE
therefore
The distance from the bucket to the ground is 4 feet
Front face: 10.6
Left face: 9
Your answer id D
Hope this helps :D
Your question is incomplete.
If you want me to tell the ratio, its 3:2