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
Step-by-step explanation:
Draw diagonal AC
The triangle ABC has sides 17 and 25
Say AB is 17, BC is 25
Draw altitude on side BC from A , say h
h = 17 sin B
Area = 25*17 sin B = 408
sin B = 24/25
In ∆ ABC
Cos B = +- 7/25
= 625 + 289 — b^2 / 2*25*17
b^2 = 914 — 14*17 = 676
b = 26
h = 17*24/25 = 408/25 = 16.32
Draw the second diagonal BD
In ∆ BCD, draw altitude from D, say DE =h
BD^2 = h^2 + {(25 + sqrt (289 -h^2) }^2
BD^2 = 16.32^2 + (25 + 4.76)^2
= 885.6576 + 266.3424
BD = √ 1152 = 33.94 m
Answer:
x = 2
Step-by-step explanation:
Given
- 7x - 3x + 2 = - 8x - 2 ← simplify left side
- 10x + 2 = - 8x - 2 ( add 8x to both sides )
- 2x + 2 = - 2 ( subtract 2 from both sides )
- 2x = - 4 ( divide both sides by - 2 )
x = 2
Answer:
Step-by-step explanation:
The diameter of a circle is twice the radius, so the statement is false.
Do 50 multiplied by x = 8. Solve for x.
It would give you .16 which is 16%.
