Answer:
D
Explanation:
To know which is most or least cost-effective, it's not enough to look at only the per day rate, or only the time to complete. You have to multiply them to get the total cost of the project.
As you can see, Greg is the least cost-effective because he charges the most for the project.
Answer:
a)
b)
Explanation:
Previous concepts
The cumulative distribution function (CDF) F(x),"describes the probability that a random variableX with a given probability distribution will be found at a value less than or equal to x".
The exponential distribution is "the probability distribution of the time between events in a Poisson process (a process in which events occur continuously and independently at a constant average rate). It is a particular case of the gamma distribution".
Part a
Let X the random variable of interest. We know on this case that
And we know the probability denisty function for x given by:
In order to find the cdf we need to do the following integral:
Part b
Assuming that , then the density function is given by:
And for this case we want this probability:
And evaluating the integral we got:
Answer:
Explanation:
Given data:
Diffusion constant for nitrogen is
Diffusion flux
concentration of nitrogen at high presuure = 2 kg/m^3
location on which nitrogen concentration is 0.5 kg/m^3 ......?
from fick's first law
Take C_A as point on which nitrogen concentration is 2 kg/m^3
Assume X_A is zero at the surface