A parabolic satellite dish reflects signals to the dish’s focal point. An antenna designer analyzed signals transmitted to a satellite dish and obtained the probability density function f(x) = c(1 - 1/16x^2) for 0 < x < 3, where X is the distance (in meters) from the centroid of the dish surface to a reflection point at which a signal arrives. Determine the value of c that makes f(x) a valid probability density function

Respuesta :

Answer:

[tex]c=\frac{16}{39}[/tex]

Step-by-step explanation:

The probability density function is :

[tex]f(x)=c(1-\frac{1}{16}x^{2})[/tex]

With 0 < x < 3

To be a valid probability density function :

[tex]\int\limits^b_a {f(x)} \,dx=1[/tex]

Where a < x < b

And also

f(x) ≥ 0 for a < x < b

Applying this to the probability density function of the exercise :

[tex]\int\limits^3_0 {c(1-\frac{1}{16}x^{2})} \, dx=1[/tex]

[tex]c\int\limits^3_0 {(1-\frac{1}{16}x^{2})} \, dx=1[/tex]

[tex]c(3-\frac{1}{16}\frac{3^{3}}{3})=1[/tex]

[tex]c(\frac{39}{16})=1[/tex]

[tex]c=\frac{16}{39}[/tex]

We can verify by replacing ''c'' in the original probability density function and integrating :

[tex]\int\limits^3_0 {\frac{16}{39}(1-\frac{1}{16}x^{2})} \, dx=[/tex]

[tex]=\frac{16}{39}.(3)-\frac{1}{39}.(\frac{3^{3}}{3})=\frac{16}{13}-\frac{3}{13}=\frac{13}{13}=1[/tex]

Also, f(x) ≥ 0 for 0 < x < 3

The value of c that makes f(x) a valid probability density function is 16/39

The probability density function is given as:

f(x) = c(1 - 1/16x^2) for 0 < x < 3

For f(x) to be valid, the following must be true

[tex]\int\limits^b_a f(x) \ dx= 1[/tex]

So, we have:

[tex]\int\limits^3_0 c(1 - \frac{1}{16}x^2) \ dx= 1[/tex]

Factor out c

[tex]c\int\limits^3_0 (1 - \frac{1}{16}x^2) \ dx= 1[/tex]

Integrate the function

[tex]c[ x - \frac{1}{48}x^3]|\limits^3_0= 1[/tex]

Expand

[tex]c[3 - \frac{1}{48}*3^3]= 1[/tex]

[tex]c[3 - \frac{27}{48}]= 1[/tex]

[tex]\frac{117}{48}c= 1[/tex]

Solve for c

[tex]c= \frac{48}{117}[/tex]

Simplify

[tex]c= \frac{16}{39}[/tex]

Hence, the value of c is 16/39

Read more about probability at:

brainly.com/question/25638875