Math

posted by .

The average travel time to work for a person living and working in​ Kokomo, Indiana is 17 minutes. Suppose the standard deviation of travel time to work is 4.5 minutes and the distribution of travel time is approximately normally distributed.
What is the travel time to work that separates the bottom​ 2.5% of people with the median or​ 50%? Round to the nearest tenth of a minute.

  • Math -

    50% in a normal distribution = median = mean

    Z = (score-mean)/SD

    Look in the back of your statistics textbook for a table called something like “area under normal distribution” to find the proportion/probability (.025) and its Z score. Insert into equation above and solve for score.

    Subtract one score from the other.

  • Math -

    Im still not understanding

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. statistics

    a study of the time spent shopping in a supermarket for a market basket of 20 specific items showed an approximately uniform distribution between 20 minutes and 40 minutes. What is the probability that the shopping time will be a) …
  2. statistics

    The time required to travel downtown at am on Monday morning is known to be normally distrubted with a mean of 40 minutes and a standard deviation of 5 minute what is the probability that it will take less than 40 minutes?
  3. Statistics

    Suppose an automobile association reports that the average time it takes to respond to an emergency call is 25 minutes. Assume the variable is approximately normally distributed and the standard deviation is 4.5 minutes. If 104 calls …
  4. Statistics

    Suppose that the travel time from your home to your office is normally distributed with a mean of 40 minutes and standard deviation of 7 minutes. If you want to be 95% certain that you will not be late for an office appointment at …
  5. statistics

    According to the Census Bureau's 2002 American Community Survey, the average travel time to work of workers 16 years and over living in Boston, MA, who did not work at home, was 28.2 minutes with a standard deviation of 0.79 minutes. …
  6. statistics

    According to the Census Bureau's 2002 American Community Survey, the average travel time to work of workers 16 years and over living in Boston, MA, who did not work at home, was 28.2 minutes with a standard deviation of 0.79 minutes. …
  7. math 540

    suppose it takes a college student an average of 5 minutes to find a parking space on the schools parking lot. Assume also that this time is normally distributed with a standard deviation of 2 minutes. What time is exceeded by approximately …
  8. Statistics (44)

    The travel-to-work time for residents of the 15 largest cities in the United States is reported in the 2003 Information Please Almanac. Suppose that a preliminary simple random sample of residents of San Francisco is used to develop …
  9. Statistics

    1. The average time it takes for a cellphone to reboot is 3 minutes with a standard deviation of 10 seconds. The average time it takes a computer to restart is 5 minutes with a standard deviation of 15 seconds. Both are normally distributed. …
  10. Math

    The average travel time to work for a person living and working in​ Kokomo, Indiana is 19 minutes. Suppose the standard deviation of travel time to work is 4.5 minutes and the distribution of travel time is approximately normally …

More Similar Questions