Question

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7. What z-score value separates the highest 10% of the scores in a normal distribution from the lowest 90%? 8. Scores on the SAT form a normal distribution with a mean of μ-550 with σ 100. If the state college only accepts students who score in the top 65% on the SAT, what is the minimum score needed to be accepted? What does that z-score become if they change their criteria so that only the top 72% are accepted? 9. For a normal population with a mean of μ-80 and a standard deviation of σ-10, what is the probability of obtaining a sample mean less than M 75 for a sample of n 25 scores? What about for a sample mean greater than M- 82 for a sample of n100 scores? 10. What happens to the standard error of M as sample size increases? 11, A sample is selected from a normal population with μ-50 and σ-12. Which of the following samples would be considered extreme and unrepresentative for this population? a. M- 53 and n 16 c. M 56 and n16 b. M-53 and n 4 d. M 56 and n4

Answer 1

7. For this value, find the cumulative area in the normal distribution table that is closest to 0.9000 (the 90th percentile.) The area 0.8997 corresponds to a z-score of 1.28.

Please post the other questions separately as we are supposed to answer just one question or four sub parts of the same question.