MIDDLE GROUND - Normal Distributions
-- Use the Traditional Stat Table Areas as Probabilities

Traditional Stat Table Area Under the Standard Normal Curve       Click on the table below to go to a page from which the table may be printed. Then, return to this page.       The table, the "Cumulative Probability from the Mean to the Z-Score," states 620 intervals (310 in pink on the right and the unstated 310 on the mirror-image left), rather than the 9 stanine intervals you used on the last page. MouseOver the arrow to see the answer. a. What percent of scores are between 0 and .15? b. What percent of scores are between 0 and -.15? c. What percent of scores are between 0 and 2.09? d. What percent of scores are between 0 and -3.3? e. What percent of scores are greater than 1.25? f. What percent of scores are between -.75 and .25? g. What percent of scores are smaller than 1.25? h. What percent of scores are greater than -2.05? i. State the z-score such that 48.46% of scores are between 0 and z.

 

 

Questions with Answer Page   1. State the area under the standard normal curve between z-scores of 0 and 1.42.   2. Given the standard normal distribution, compute p(z is within 1.42 standard deviations of the mean), p(-1.42 < z < 1.42).   3. Given the standard normal distribution, find the z-score such that p(z is within __ standard deviations of the mean) = 95%.   4. Find, to two decimal places accuracy, the boundaries in the standard normal distribution, such that p(z is within __ standard deviations of the mean) = 74.98%.   5. Using the z-scores in the above table, state the lowest z-score which is in the top 90% of all scores.   6. Using the z-scores in the above table, state the lowest z-score which is in the top 85% of all scores.   7. Compute: p(-2.2 < z < -2.35).   8. Compute, given a normal distribution, = 3 and s = 0.4, p(2 < x < 4).

 

 

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