Explore BrainMass

Explore BrainMass

    Probability and Samples

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    I have a random sample of n = 16 scores with a normal distribution, mean of 50 and standard deviation of 10. I need to calculate what range of values has a 95% probability of containing the sample mean.

    Here is where I get stuck. I have been provided the answer and it is 45.13 to 54.87 (50 +/- 4.87). I don't know how to get there. To me, 1/2 of the scores I am looking for are above the mean (50) and 1/2 are below. 1/2 of 95% is 47.5. On the z-score chart under "d" .4750 provides a z-score of 1.96. I have already calculated the standard error as 2.5. 1.96(2.5) = 4.9, so the answer would be 50 +/- 4.9.

    I don't know what I am missing.

    © BrainMass Inc. brainmass.com June 3, 2020, 6:12 pm ad1c9bdddf

    Solution Summary

    This Solution contains over 100 words and calculations to aid you in understanding the Solution to these questions.