# statistics

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a mean score on a standardized test is 50 with a standard deviation of 10. What are the following:

1. what scores fall between -1 and +1 standard deviation?

2. what percent of all scores fall between -1 and +1 standard deviation?

3. what score falls at +2 standard deviations?

4. What percentage of scores falls between +1 and +2 standard deviations?

• statistics -

Z score is your score in terms of standard deviations.

Z = (score-mean)/SD

For the percentages, find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score. Multiply by 100 for the percentage.

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