math

posted by .

for a sample of n = 75, find the probaBILITY OF A SAMPLE MEAN BEING BEIGN GREATER THAN 221 IF U = 220 AND O = 3.9

  • math -

    First, please do not use all capitals. Online it is like SHOUTING. Not only is it rude, but it is harder to understand. Thank you.

    I assume "U" = mean and "O" = standard deviation.

    Z = (mean1 - mean2)/standard error (SE) of difference between means

    SEdiff = √(SEmean1^2 + SEmean2^2)

    SEm = SD/√(n-1)

    Since only one SD is provided, you can use just that to determine SEdiff.

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

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Statistics

    he Oil Price Information Center reports the mean price per gallon of regular gasoline is $ 3.79 with a population standard deviation of $ 0.18. Assume a random sample of 40 gasoline stations is selected and their mean cost for regular …
  2. statistics

    for a sample of n = 36, find the probability of a sample mean being less than 12.2 if u = 12 and o = 0.95
  3. statistics

    The population mean and standard deviation are given. Find the required probability and determine whether the given sample mean would be considered unusual. For a sample of n=36, find the probability of a sample mean being less than …
  4. statistics

    Find a number 't' such that the probability that the sample mean will differ from the population mean by at least 't' is not greater than 0.05 if the sample size is 100 and sigma is 3
  5. Math- Statistics

    A random sample of size 36 is to be selected from a population that has a mean μ = 50 and a standard deviation σ of 10. * a. This sample of 36 has a mean value of , which belongs to a sampling distribution. Find the shape …
  6. statistics

    The population of SAT scores forms a normal distribution with a mean of µ =500 and a standard deviation of σ =100. If the average SAT score calculated for a sample of n = 25 students, a. What is the probability that the sample …
  7. probability and statistics

    the population of sat scores forms a normal distribution with a mean of u=500 and a standard deviation of o=100. if the average sat score is calculated for a sample of n=25 students. a. what is the probability that the sample mean …
  8. Statistics

    A university has 1,000 computers available for students to use. Each computer has a 250-gigabyte hard drive. The university wants to estimate the space occupied on the hard drives. A random sample of 100 computers showed a mean of …
  9. Statistical inference

    Suppose the results for stat 201 in 2014 are normally distributed with mean 160 and standard deviation 18 . Find the probability that a random sample of size 36 gives a sample mean value in the following cases Question : between 120 …
  10. statistics help

    Tests on a Chevy Cobalt incdicate a population mean of 32 mpg and a population standard deviation of 3.5 mpg. You take an SRS (sample random sample) of 10 cars to get a sample mean. What is the probability that your sample mean is …

More Similar Questions