math

posted by .

The average middle-distance runner at a local high school runs the mile in 4.5 minutes, with a standard deviation of 0.3 minute. The percentage of a runners that will run the mile in less than 4 minutes is %.

  • math -

    .5/.3 = 1.67 standard deviations below mean
    Look at table for normal distribution
    My quick table is very rough
    for z = -1.6 F(z) = .055
    for z = -1.7 F(z) = .045
    so about F(1.67) = about .05 or 5 %

    By the way, I do not believe it. Suspect sigma much lower than 0.3 min or possibly not a normal distribution at all.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    In 1954, Roger Bannister became the first human to run a mile in less than 4 minutes. Suppose that a runner on a straight track covers a distance of 1.00 mi in exactly 4.00 min. 1. What is his average speed in mi/h?
  2. statistics

    The average middle-distance runner at a local high school runs the mile in 4.5 minutes, with a standard deviation of 0.3 minute. Find the percentage of a runners that will run the mile in less than 4 minutes?
  3. Math

    A goal for elite runners is to complete a mile in 4 minutes. At what speed(in miles per hour) is a runner traveling when he completes a mile in 4 minutes?
  4. psychology

    If the mean score on a one mile running test was 14 minutes and the standard deviation was 1 minute what percentage of subjects ran the mile in 15 minutes or less
  5. math

    the average middle distance runner at a local high school runs the mile in 4.5 minutes with a standard deviation of 0.3 minute the percentage of a runners that will run the mile in less than 4 min is %
  6. physics

    in 1954 roger bannister became the first human to run a mile in less than 4 minutes. suppose that a runner on a straight track covers a distance of 1.00 mi in exactly 4.00 min. What is the average speed in mi/h What is his average …
  7. math

    Two runners are competing in a race. One runner averages a pace of 7 minutes per mile and finishes the race in 28 minutes. The second runner finishes the race in 30 minutes. Which of the following is the pace of the second runner?
  8. 7th Grade Math

    Sarah ran her first mile in 8 minutes. Her next mile was run in 6 minutes. What was the percent decrease in her mile time?
  9. Math

    Sheldon is a long-distance runner he can run a mile in 6 4/5 minutes how many miles can he run in 30 minutes
  10. math

    Three students are arguing over who can run the fastest. Student A says that she can run mile in six minutes. Student B says that he can run mile in four minutes. Student C says that he can run mile in eight minutes.What fraction of …

More Similar Questions