B is the answer because the value of x does not repeat
Answer:
Step-by-step explanation:

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:
1. 78cm^2
2. 200 ft^2
Step-by-step explanation:
1. i always cut these complex shapes into simpler ones (in this case a rectangle and a triangle)
the rectangles area is 6*8 or 48 and the triangles area is (10*6)/2 or 30 you then add the two areas to get the area for the whole shape 48+30=78
2. once again you're going to break this shape up into the individual rooms and then add them together the garage is a 4*6 room (24) the bedroom is a 8*4 room (32) the living room is a 10*10 room (100) the kitchens a 6*6 room (36) and the bathroom is a 4*2 room (8) you then add all these together
24+32+100+36+8=200