A regulation hockey puck must weigh between 5.5 and 6 ounces. The weights X of pucks made by a particular process are normally distributed with mean 5.75 ounces and standard deviation 0.11 ounce. Find the probability that a puck made by this process will meet the weight standard.

Respuesta :

Answer:

[tex]P(5.5<X<6)=P(\frac{5.5-\mu}{\sigma}<\frac{X-\mu}{\sigma}<\frac{6-\mu}{\sigma})=P(\frac{5.5-5.75}{0.11}<Z<\frac{6-5.75}{0.11})=P(-2.27<z<2.27)[/tex]

And we can find this probability with this difference:

[tex]P(-2.27<z<2.27)=P(z<2.27)-P(z<-2.27)=0.988 -0.0116=0.9764[/tex]

Step-by-step explanation:

Let X the random variable that represent the weights of a population, and for this case we know the distribution for X is given by:

[tex]X \sim N(5.75,0.11)[/tex]  

Where [tex]\mu=5.75[/tex] and [tex]\sigma=0.11[/tex]

We are interested on this probability

[tex]P(5.5<X<6)[/tex]

And we can use the z score formula given by:

[tex]z=\frac{x-\mu}{\sigma}[/tex]

If we apply this formula to our probability we got this:

[tex]P(5.5<X<6)=P(\frac{5.5-\mu}{\sigma}<\frac{X-\mu}{\sigma}<\frac{6-\mu}{\sigma})=P(\frac{5.5-5.75}{0.11}<Z<\frac{6-5.75}{0.11})=P(-2.27<z<2.27)[/tex]

And we can find this probability with this difference:

[tex]P(-2.27<z<2.27)=P(z<2.27)-P(z<-2.27)=0.988 -0.0116=0.9764 [/tex]