Assume that the wavelengths of photosynthetically active radiations (PAR) are uniformly distributed at integer nanometers in the red spectrum from 625 to 640 nm. What is the mean and variance of the wavelength distribution for this radiation? Round your answers to one decimal place (e.g. 98.7).

Respuesta :

Answer:

[tex] E(X) = \frac{625+640}{2}=632.5[/tex]

[tex]Var(X)= \frac{(b-a)^2}{12}=\frac{(640-625)^2}{12}=18.75 \approx 18.8[/tex]

[tex] \mu= 632.5, \sigma^2 = 18.8[/tex]

Step-by-step explanation:

Let X the random variable that represent "The wavelengths of photosynthetically active radiations PAR ". And we know that the distribution of X is given by:

[tex]X\sim Uniform(a=625 ,b=640)[/tex]

The density function is given by:

[tex] f(x) = \frac{1}{b-a} , a \leq x \leq b[/tex]

And [tex] f(x)=0[/tex] for other case.

The mean for this case is given by:

[tex] E(X)=\frac{a+b}{2}[/tex]

And if we replace we got:

[tex] E(X) = \frac{625+640}{2}=632.5[/tex]

For the variance of the random variable X we can use the following formula:

[tex]Var(X)= \frac{(b-a)^2}{12}=\frac{(640-625)^2}{12}=18.75 \approx 18.8[/tex]

So then the answer would be:

[tex] \mu= 632.5, \sigma^2 = 18.8[/tex]