Answer:
![t=5.0days](https://tex.z-dn.net/?f=t%3D5.0days)
Step-by-step explanation:
Using the formula for the exponential decay that is
, we have N=
,
and k=0.1374.
Thus,
becomes
![23=46{\times}e^{-0.1374t}](https://tex.z-dn.net/?f=23%3D46%7B%5Ctimes%7De%5E%7B-0.1374t%7D)
![\frac{23}{46}=e^{-0.1374t}](https://tex.z-dn.net/?f=%5Cfrac%7B23%7D%7B46%7D%3De%5E%7B-0.1374t%7D)
![\frac{1}{2}=e^{-0.1374t}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%3De%5E%7B-0.1374t%7D)
Taking log on both sides, we get
![ln(\frac{1}{2})={-0.1374t}](https://tex.z-dn.net/?f=ln%28%5Cfrac%7B1%7D%7B2%7D%29%3D%7B-0.1374t%7D)
![t=\frac{ln\frac{1}{2}}{-0.1}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7Bln%5Cfrac%7B1%7D%7B2%7D%7D%7B-0.1%7D)
![t=\frac{-0.6931}{-0.1374}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B-0.6931%7D%7B-0.1374%7D)
![t=5.0days](https://tex.z-dn.net/?f=t%3D5.0days)
In a symmetric distribution, better known as the Gaussian or normal distribution, two thirds of the observations or 66.67% of the observation belongs to the area between the -3∅ to +3∅ where ∅ is the standard deviation of the group. it is assumed here that the mean is 1 and the area under the curve is also 1.
Answer:
45 miles in 1 hour
Step-by-step explanation:
1 hour is 60 minutes
22.5 miles / 30 minutes * 2/2 = 45 miles / 60 minutes = 45 miles in 1 hour
12(3x + 5y) |use distributive property: a(b + c) = ab + ac
= (12)(3x) + (12)(5y) = 36x + 60y