So the best way to do these is concentration1 (%) × volume1 = concentration2 × volume2
Or C1V1 + C2V2 = C3V3, where C1 = 100% (bc ALL pecans), V1 = 6 lbs, C2 = 70%, C3 = 82%:
100%×6 + 70%×v2 = 82%×(6+v2)
100%=1.00, 70%=.7, 82%=.82
note: if none is poured out then v3 = v1+v2
6 + .7v2 = .82 (6+v2)
6 + .7v2 = 4.92 + .82v2
6 + .7v2 -.7v2 = 4.92 + .82v2 -.7v2
6 = 4.92 + .12v2
6-4.92 = 4.92-4.92 + .12v2
1.08 = .12v2
.12v2/.12 = 1.08/.12
v2 = 9 lbs
that's only v2!!!
For the final poundage, we need v3:
v3 = 6 + v2 = 6 + 9 = 15 lbs
Yeah sure! Just make sure to post them haha :)
Answer:
The standard deviation (σ) = 0.05
Step-by-step explanation:
The question is to find the standard deviation.
STEEP 1: FIND THE MEAN
(10+9.9) ÷ 2 = 9.95
STEP 2: SQUARE THE DIFFERENCE BETWEEN SPRINT TIME AND MEAN
10-9.95= 0.05
0.05^2 = 0.0025
9.9 - 9.95= -0.0025
-0.0025^2 = 0.0025
STEP 3: FIND THE VARIANCE
0.0025+0.0025= 0.005
0.005/2= 0.0025
STEP 4: FIND THE STANDARD DEVIATION (σ )
√variance
√0.0025 = 0.05
Therefore
σ = 0.05.
From the standard deviation, the percentage probability of the higher value to occurs is
0.05×100= 5%
That means Doug has 95%
And Bob has 5%
The bones at the time they were discovered when the radioactive element carbon-14 has a half-life of total 5750 years are 10062.5-year-old.
<h3>What is half-lives?</h3>
Half lives is the time interval which is need to decay the atomic nuclei of a radioactive sample.
There is a scientist who determined that the bones from a mastodon had lost 70.3% of their carbon-14. Thus, the fraction remaining is,
f=1-(70.3/100)=1-0.703
f=1-(70.3/100)=0.297
Now the fraction remaining can be given as,
f=(1/2)ⁿ
Here, n is the half life elapsed. Put the value of fraction remaining.
0.297=(1/2)ⁿ
n=1.75
The radioactive element carbon-14 has a half-life of total 5750 years. Thus,
Years=1.75*5750
Years=10062.5
Thus, the bones at the time they were discovered when the radioactive element carbon-14 has a half-life of total 5750 years are 10062.5-year-old.
Learn more about the half lives here;
brainly.com/question/2320811
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