brookeless
contestada

The speeds on the interstate are normally distributed with a mean of 70 mph and a standard deviation of 5 mph. Approximately what percent of speeds fall between 60 mph and 80 mph?

Respuesta :

LammettHash
[tex]\mathbb P(60<X<80)=\mathbb P\left(\dfrac{60-70}5<\dfrac{X-70}5<\dfrac{80-70}5\right)=\mathbb P(-2<Z<2)[/tex]

The empirical rule asserts that approximately 95% of a distribution falls within two standard deviations of the mean.