Answer:
yes
Step-by-step explanation:
Answer:
it will take 5 hours
Step-by-step explanation:
It will take five hours because first you take 300 and 60 and divide them to get 5.
The half-life of Po is 139 days, so its decay rate is
0.5 = e^(139k) ==> k = ln(0.5)/139
After some time t, 80% of the material will have decayed and you'll be left with a sample 20% of its original mass:
0.2 = e^(kt) ==> t = ln(0.2)/k = ln(0.2)/ln(0.5) * 139 = 322.748
so your sample is usable for about 323 days.
Answer:
a. P(X<5)=0.729
Step-by-step explanation:
<em>The question is incomplete:</em>
<em>"The port of South Louisiana, located along miles of the Mississippi River between New Orleans and Baton Rouge, is the largest bulk cargo port in the world. The U.S. Army Corps of Engineers reports that the port handles a mean of 4.5 million tons of cargo per week. Assume that the number of tons of cargo handled per week is normally distributed with a standard deviation of 0.82 million tons.</em>
<em>a. What is the probability that the port handles less than 5 million tons of cargo per week (to 4 decimals)."</em>
We can solve this using the z-score.
We have a normal distribution with mean 4.5 and standard deviation 0.82.
The z-score for X=5 is:
![z=\dfrac{X-\mu}{\sigma}=\dfrac{5-4.5}{0.82}=\dfrac{0.5}{0.82}=0.6098](https://tex.z-dn.net/?f=z%3D%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%7D%3D%5Cdfrac%7B5-4.5%7D%7B0.82%7D%3D%5Cdfrac%7B0.5%7D%7B0.82%7D%3D0.6098)
Then, the probability that X<5 is: