SOLUTION: An executive at Hughes drives from his home to work every day. The driving times are normally distributed with a mean of 35 minutes and a standard deviation of 8 minutes.
Algebra.Com
Question 647788: An executive at Hughes drives from his home to work every day. The driving times are normally distributed with a mean of 35 minutes and a standard deviation of 8 minutes.
a. In what percent of the days will it take him 30 or fewer minutes to reach his office?
b. What percent of the days will it take between 40 and 50 minutes?
c. What percent of days will it take him between 30 and 45 minutes?
d. How long will the longest 10% of the trips take?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
An executive at Hughes drives from his home to work every day. The driving times are normally distributed with a mean of 35 minutes and a standard deviation of 8 minutes.
a. In what percent of the days will it take him 30 or fewer minutes to reach his office?
------
z(30) = (30-35)/8 = -5/8
P(x <= 30) = P(z <= -5/8) = normalcdf(-100,-5/8) = 0.2660 = 26.60%
==================
b. What percent of the days will it take between 40 and 50 minutes?
Find the z-scores.
Find the percentage between those z-scores.
================================================
c. What percent of days will it take him between 30 and 45 minutes?
Same procedure as on "b".
============================
d. How long will the longest 10% of the trips take?
Find the z-value with a left tail of 0.90
invNorm(0.9) = 1.2815
------
x = zs + u
x = 1.2815*8+35 = 45.25
================================
Cheers,
Stan H.
RELATED QUESTIONS
An executive drives from his home in Portmore to his office at the Bank of Jamaica. The... (answered by Boreal)
An executive at Westinghouse drives from her home in the suburbs near Pittsburgh to her... (answered by Boreal)
In a large U.S. city a study was conducted to determine the typical commute time from... (answered by stanbon)
A man leaves his home every morning at 07h45 for his work which starts at 08h00. The time (answered by stanbon)
John drives from his house to a beach 150 miles away, and at the end of the day drives... (answered by solver91311)
The time a group of high school students arrive home from school each day was found to be (answered by fractalier)
I am having a very hard time with this problem! Please help!
The time a group of... (answered by stanbon)
John can take on three possible routes from his home to his oce in the
morning. The... (answered by Glaviolette)
John can take on three possible routes from his home to his office in the morning. The... (answered by ikleyn)