contestada

Question 1

2 pts

(09.05)

At an intersection, the red light times are normally distributed

with a mean time of 3 minutes and a standard deviation of 0.25

minutes. Approximately what percent of red lights last between

2.5 and 3.5 minutes? (2 points)

32%

68%

Respuesta :

JeanaShupp

Answer: The percent of red lights last between  2.5 and 3.5 minutes = 95.44% approx.

Step-by-step explanation:

Given: Mean time = 3 minutes

standard deviation = 0.25 minutes

The probability of red lights last between  2.5 and 3.5 minutes :-

[tex]P(2.5<x<3.5)\\\\=P(\dfrac{2.5-3}{0.25}<\dfrac{x-\mu}{\sigma}<\dfrac{3.5-3}{0.25})\\\\=P(-2<z<2)\\\\=2P(Z<2)-1\\\\=2(0.9772)-1\\\\=0.9544[/tex]

The percent of red lights last between  2.5 and 3.5 minutes = 95.44% approx.