Consider babies born in the "normal" range of 37 - 43 weeks gestational age. Extensive data supports the assumption that for such babies born in the United States, birth weight is normally distributed with mean = 3432 grams and standard deviation = 482 grams.
What is the probability that the birth weight of a randomly selected baby of this type:
a. is between 3000 and 4000 grams
b. exceeds 4000 grams
c. is either less than 2000 grams or greater than 5000 grams
d. is no more than 3432 grams
The personnel office at a large electronics firm regularly schedules job interviews and maintains
records of the interviews. From the past records, they have found that the length of a first interview is normally distributed with mean = 35 minutes and standard deviation = 6 minutes. Nine first interviews are usually scheduled per day.
a. Find the mean and standard deviation of the sampling distribution of the mean length of time of the nine interviews .
b. Find the probability that the average length of the nine interviews is less than 29 minutes.
c. Find the probability that the average length of the nine interviews is between 32 and 38 minutes.
d. Find the probability that the average length of the nine interviews is at least 39 minutes.
e. Find the probability that the average length of the nine interviews is at most 35 minutes.