An Internet reaction time test asks subjects to click their mouse button as soon as a light flashes on the screen. The light is programmed to go on at a randomly selected time after the subject clicks "Start." The density curve models the amount of time the subject has to wait for the light to flash. a. What height must the density curve have? Justify your answer. b. About what percent of the time will the light flash more than 3.75 seconds after the subject clicks "Start"? c. Calculate and interpret the 38th percentile of this distribution.

Respuesta :

Using the uniform distribution, it is found that:

a) The height of the density curve is of 0.25.

b) 31.25% of the time will the light flash more than 3.75 seconds after the subject clicks "Start".

c) The 38th percentile of this distribution is of 2.52 seconds. It means that 38% of the time, the light will go on in at most 2.52 seconds.

Uniform distribution:

An uniform distribution has two bounds, a and b.  

The probability of finding a value of at lower than x is:

[tex]P(X < x) = \frac{x - a}{b - a}[/tex]

The probability of finding a value between c and d is:

[tex]P(c \leq X \leq d) = \frac{d - c}{b - a}[/tex]

The probability of finding a value above x is:

[tex]P(X > x) = \frac{b - x}{b - a}[/tex]

In this problem, uniform between 1 and 5, hence [tex]a = 1, b = 5[/tex]

Item a:

The height of the uniform distribution is:

[tex]h = \frac{1}{b - a}[/tex]

Hence:

[tex]h = \frac{1}{5 - 1} = 0.25[/tex]

Item b:

[tex]P(X > 3.75) = \frac{5 - 3.75}{5 - 1} = 0.3125[/tex]

0.3125 x 100% = 31.25%

31.25% of the time will the light flash more than 3.75 seconds after the subject clicks "Start".

Item c:

The 38% percentile is x for which P(X < x) = 0.38, hence:

[tex]P(X < x) = \frac{x - a}{b - a}[/tex]

[tex]0.38 = \frac{x - 1}{4}[/tex]

[tex]x - 1 = 4(0.38)[/tex]

[tex]x = 2.52[/tex]

The 38th percentile of this distribution is of 2.52 seconds. It means that 38% of the time, the light will go on in at most 2.52 seconds.

A similar problem is given at https://brainly.com/question/15855314