stat.

posted by .

The average age of a vehicle registered in the United States is 8 years, or 96 months. Assume the standard deviation is 16 months. If a random sample of a group of 48 vehicles is selected find the probability that the mean of the group’s age is between 90 and 100 months.

  • stat. -

    Z = (score-mean)/SEm

    SEm = SD/√n

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

    This is a distribution of means, while your next post is a distribution of raw scores.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. statistics

    The average age of statistics students nationwide is 22. The standard deviation is 2.5 years. Assume the age is a normally distributed variable. Find the probability that one student selected at random is older than 23. Find the probability …
  2. Statistics

    The average age of chemical engineers is 37 years with a standard deviation of 4 years. If an engineering firm employs 25 chemical engineers, find the probability that the average age of the group is greater than 38.2 years old. If …
  3. statistics

    The average age of a vehicle registered in the U.S. is 8 years, or 96 months. If a random sample of 36 vehicles is selected, find the probability that the mean of their age is between 98 and 100 months. Assume the standard deviation …
  4. statistics

    The average age of a child in kindergarden is 5 years or 60 months. The standard deviation is 12 months. If a random child is selected, find the probability that the childs age is between 54 and 66 months.
  5. science

    Shown below are the data giving the length of life of lights in an underground tunnel. 9.0 months 7.0 months 8.2 months 8.3 months 7.8 months 8.1 months 7.5 months 7.6 months 9.1 months 7.4 months I calculated the standard deviation …
  6. Statistics

    Shown below are the data giving the length of life of lights in an underground tunnel. 9.0 months 7.0 months 8.2 months 8.3 months 7.8 months 8.1 months 7.5 months 7.6 months 9.1 months 7.4 months I calculated the standard deviation …
  7. Statistics

    The average age of vehicles registered in the united states is 96 months, with a standard deviation of 16 months. If a random sample of 36 vehicles is selected, find the probability that the mean of their ages is between 90 and 100 …
  8. stats

    2. The average age of a child in kindergarten is 66 months. The standard deviation is 4 months. If a random child is selected, find the probability that the mean age is: a) Between 64 and 68 months b) Greater than 62 months
  9. statistics

    The average age of a vehicle registered in the United States is 8 years, or 96 months. Assume the standard deviation is 16 months. If a random sample of a group of 48 vehicles is selected find the probability that the mean of the group’s …
  10. Stats.

    The average age of a vehicle registered in the United States is 8 years, or 96 months. Assume the standard deviation is 16 months. If a random sample of a group of 48 vehicles is selected find the probability that the mean of the group’s …

More Similar Questions