math

posted by .

The lifetime of a SuperTough AAA battery is normally distributed with mean of 28.5 hours and standard deviation of 5.3 hours. For a battery selected at random, what is the probability that the lifetime will be 34 hours or less?

  • math -

    Z = (score-mean)/SD

    Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Statistics

    The lifetime of a 2-volt non-rechargeable battery in contant use has a normal distribution with a mean of 516 hours and a standard deviation of 20 hours. Ninety percent of all batteries have a lifetime less than ?
  2. Statistics

    The lifetime of a 2-volt non-rechargeable battery in contant use has a normal distribution with a mean of 516 hours and a standard deviation of 20 hours. Ninety percent of all batteries have a lifetime less than ?
  3. STATISTICS HELP

    The lifetime of a disk drive head is normally distributed with a population mean of 1000 hours and standard deviation of 120 hours. Determine the probability that the average lifetime for 9 disk drives will exceed 940 hours. Need to …
  4. Math

    The lifetime of a SuperTough AAA battery is normally distributed with mean of 28.5 hours and standard deviation of 5.3 hours. For a battery selected at random, what is the probability that the lifetime will be 25 hours or less?
  5. Statistics

    The lifetime of a certain smart phone battery has an unknown distribution with mean value of 8 hours and standard deviation of 2 hours. What is the approximate probability that the average battery lifetime of a sample of 36 batteries …
  6. Statistics

    The lifetime of a certain smart phone battery has an unknown distribution with mean value of 8 hours and standard deviation of 2 hours. What is the approximate probability that the average battery lifetime of a sample of 36 batteries …
  7. statistics

    Urgen!! Statistics homework help? Your company is producing special battery packs for the most popular toy during the holiday season. The life span of the battery pack is known to be Normally distributed with a mean of 250 hours and
  8. statistics

    The lifetime of a 2 volt non- rechargeable battery has a normal distribution with a mean of 516 hours and a standard deviation of 20 hours.What is the z- score for batteries with lifetimes of 600 hours
  9. statistics

    The lifetime of a 2-volt non-rechargeable battery in constant use has a normal distribution with a mean of 516 hours and a standard deviation of 20 hours. Ninety percent of all batteries have a lifetime less than
  10. math

    the battery lifetime is normally distributed for large samples with a standard deviation of 70 days. if 16% of the batteries have a lifetime of 850 or higher, what is the average battery life?

More Similar Questions