time 2nd 5/5 it become 35/5x-20
2/5x-20+35/5x-20
=37/5x-20
Answer:
yes you may use the answer will be 100% correct
We have 5% and 6.5% acetic acid solutions and we need 200 ml of 6% acetic acid.
Set up two equations:
f means 5% and s means 6.5%
A) f + s = 200
B) .05f + .065s = (.06 * 200)
Multiplying equation A by -.05
A) -.05f -.05s = -10
B) .05f + .065s = 12 then adding both equations:
.015s = 2
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we need 133.33</span> ml of 6.5% acetic acid and
66.67 ml of 5% acetic acid solution.
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Source:
http://www.1728.org/mixture.htm
19.884 miles, because 1km=0.621 mile
Answer:
The 99% confidence interval would be given by (0.286;0.562)
Step-by-step explanation:
Information given:
represent the families owned at least one DVD player
represent the total number of families
represent the estimated proportion of families owned at least one DVD player
In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 99% of confidence, our significance level would be given by 
and 
. And the critical value would be given by:
The confidence interval for the mean is given by the following formula:
If we replace the values obtained we got:
The 99% confidence interval would be given by (0.286;0.562)
