Answer:
A sample of 17 must be selected.
Step-by-step explanation:
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 Z-table as such z has a p-value of 
.
That is z with a pvalue of 
, so Z = 2.054.
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
The standard deviation from a previous study is 4 hours.
This means that 
How large a sample must be selected if he wants to be 96% confident of finding whether the true mean differs from the sample mean by 2 hours?
A sample of n is required.
n is found for M = 2. So
Simplifying both sides by 2:
Rounding up:
A sample of 17 must be selected.
6 1/3=19/3
8.25=8 1/4=33/4
in multiplying fraction, all you have to do is
multiply the numerators 19x33=627
same with the denominators 3x4=12
627/12 reduce if possible
209/4
Answer:
D. 6.3
Step-by-step explanation:
Well you can make a triangle with the line PQ with it's height as 2 and base as 6.
Then you can use the Pythagorean Theorem to find the length of PQ.
a²+b²=c²
2²+6²=c²
4+36=c²
40=c²
c²=40
<em>Square root both sides</em>
c=
c≈6.3
Our answer is D. 6.3
Step-by-step explanation:
2w+6w=80
w=10
l=30
