Answer:

Step-by-step explanation:
The confidence interval for the population mean x can be calculated as:

Where x' is the sample mean, s is the population standard deviation, n is the sample size and
is the z-score that let a proportion of
on the right tail.
is calculated as: 100%-99%=1%
So, 
Finally, replacing the values of x' by 308, s by 17, n by 15 and
by 2.576, we get that the confidence interval is:

In real-life physics, acceleration due to gravity will change respect to altitude. Check out the attached image (source: Wikipedia).
However, in high-school physics, acceleration due to gravity is represented by the letter g, which has a value of 9.81 meters per second squared.
This means that an object being dropped straight down will be moving 9.81 meters per second faster than it was 1 second ago. I hope this helps! :)
Answer:
It will take him 1 hour and 30 minutes. (90 minutes)
Step-by-step explanation:
If he is running 1 mile in 10 minutes and he needs to run 9 miles the just multiply 9 by 10 to get 90 then simplify if you need to to get 1 hour and 30 minutes.
Hope this helped and have a great rest of your day.
Answer:
5 pi/12
Step-by-step explanation:
To change degrees to radians, multiply by pi/180
75* pi/180
divide the top and bottom by 15
5 pi/12
Answer:
- 33 1/3 liters of 30%
- 16 2/3 liters of 45%
Step-by-step explanation:
Let x represent the liters of 45% solution needed. Then the amount of HCl in the mix is ...
0.45x +0.30(50 -x) = 0.35(50)
0.15x = 0.05(50) . . . . . simplify, subtract 0.30(50)
x = (0.05/0.15)(50) = 50/3 = 16 2/3 . . . liters of 45% HCl
33 1/3 liters of 30% and 16 2/3 liters of 45% HCl are needed.
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<em>Comment on the solution</em>
You may notice that the general solution to a mixture problem of this sort is that the fraction of the mix that is the highest contributor is ...
(mix % - low %) / (high % - low %) = (.35 -.30) / (.45 -.30) = .05/.15 = 1/3