The patient recovery time from a particular surgical procedure is normally distributed with a mean of 5.5 days and a standard deviation of 2.3 days. What is the probability of spending more than 4 days in recovery? (Round your answer to four decimal places.)

Respuesta :

Answer:

[tex]P(X>4)=P(\frac{X-\mu}{\sigma}>\frac{4-\mu}{\sigma})=P(Z>\frac{4-5.5}{2.3})=P(z>-0.652)[/tex]

And we can find this probability with the complement rule and with the normal standard table and we got:

[tex]P(z>-0.652)=1-P(z<-0.652)= 1-0.2572= 0.7428[/tex]

Step-by-step explanation:

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

[tex]X \sim N(5.5,2.3)[/tex]  

Where [tex]\mu=5.5[/tex] and [tex]\sigma=2.3[/tex]

We are interested on this probability

[tex]P(X>4)[/tex]

And we can solve this problem using the z score formula given by:

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

And using this formula we got:

[tex]P(X>4)=P(\frac{X-\mu}{\sigma}>\frac{4-\mu}{\sigma})=P(Z>\frac{4-5.5}{2.3})=P(z>-0.652)[/tex]

And we can find this probability with the complement rule and with the normal standard table and we got:

[tex]P(z>-0.652)=1-P(z<-0.652)= 1-0.2572= 0.7428[/tex]

Q&A Education