Tarea Probabilidad (Tema III)

ENES Juriquilla

F.A. Barrios

Distribución Normal

In the study of fingerprints, an important quantitative characteristic is the total ridge count for the 10 fingers of an individual. Suppose that the total ridge count of individuals in a certain population are approximately normally distributed with a mean of 140 and a standard deviation of 50. Find the probability that an individual from this population will have a ridge count of:
(a) 200 or more
(b) Less than 100
(c) Between 100 and 200
(d) Between 200 and 250
(e) In a population of 10,000 people how many would you expect to have a ridge count of 200 or more?

One of the variables in the North Carolina Birth Registry data is the pounds gained during pregnancy. According to data from the entire registry for 2001, the number of pounds gained during pregnancy was approximately normally distributed with mean of 30.23 pounds and standard deviation of 13.84 pounds. Calculate the probability that a randomly selected other in North Carolina in 2001 gained:
(a) Less than 15 pounds during pregnancy
(b) More than 40 pounds
(c) Between 14 and 40 pounds
(d) Less than 10 pounds
(e) Between 10 and 20 pounds

Suppose the average length of stay in a chronic disease hospital of a certain type of patient is 60 days with a standard deviation of 15. If it is reasonable to assume an approximately normal distribution of lengths of stay, find the probability that a randomly selected patient from this group will have a length of stay:
(a) Greater than 50 days
(b) Les than 30 days
(c) Between 30 and 60 days
(d) Greater than 90 days