Mean and standard deviation of sample mean score

Reference no: EM1321357

Q1) Scores of high school seniors on ACT college entrance examination in 2003 has mean 20.8 and standard deviation 4.8. Distribution of scores is only roughly normal.

a) What is the approximate probability that single student randomly selected from all those taking test scores 23 or higher?

b) Not take SRS of 25 students who took test. What are the mean and standard deviation of sample mean score xbar of these 25 students?

c) Compute the approximate probability that mean score xbar of these students is 23 or higher?

d) Which of your tow normal probability calculations ins (a) and (c) is more right and why?

Reference no: EM1321357

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