+ Reply to Thread
Results 1 to 3 of 3

Thread: sample mean

  1. #1
    Points: 5,150, Level: 45
    Level completed: 50%, Points required for next Level: 200

    Thanked 0 Times in 0 Posts

    Exclamation sample mean

    The population of incomes in a particular community is thought to be highly right-skewed with a mean equal to $36,789 and standard deviation equal to $2,490. Based on this, if a sample of size n=36 is selected the highest sample mean that we would expect to see would be approximately $38,034.

    My teacher said this is true, but how do I get this answer?

  2. #2
    TS Contributor
    Points: 17,636, Level: 84
    Level completed: 58%, Points required for next Level: 214
    JohnM's Avatar
    Thanked 6 Times in 5 Posts

    The sample means will have:

    1. a normal distribution with a mean equal to the population mean, and
    2. a standard error equal to the population standard deviation divided by the square root of the sample size

    Use the z-tables to figure out if 38,034 is about as high as you might expect the sample mean to get, if you took many, many samples of size 36 (probably around 3 standard errors above the sample mean....)

  3. #3
    Points: 20,637, Level: 90
    Level completed: 58%, Points required for next Level: 213
    quark's Avatar
    Thanked 196 Times in 73 Posts

    Hi Jessi,

    It's probably the 95th or 99th percentile of the sampling distribution of the mean. To get it you need to calculte the standard error of the mean first. Post here if you have further questions.

+ Reply to Thread


Similar Threads

  1. Replies: 4
    Last Post: 02-24-2011, 04:12 AM
  2. Given sample variance, find sample st. dev
    By jjs2168 in forum Statistics
    Replies: 1
    Last Post: 04-08-2009, 11:25 PM
  3. Sample size for multi-site sample
    By DLFS in forum Statistics
    Replies: 1
    Last Post: 01-27-2009, 08:44 PM
  4. sample-to-sample variability
    By klena in forum Statistics
    Replies: 0
    Last Post: 12-29-2008, 07:41 PM
  5. Sample size for repeated measures or dependent-sample t
    By Susanbwh in forum Statistical Research
    Replies: 1
    Last Post: 02-18-2006, 02:27 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Advertise on Talk Stats