Answer:
Look at it this way. About two-thirds of the populace are thought to possess IQs between 85 and 115, which is to say, more or less average. That leaves about one sixth of the populace significantly below average and one sixth significantly above average.
Why such a large range for average — there’s a 30-point gap between 85 and 115? That’s because IQ tests measure only certain kinds of intelligence, and people who might be weak in some areas might be strong in other areas. Consider the difference between being book-smart and being street-smart. A person who is book-smart would be expected to score well on an IQ test but might not fare so well in a dangerous neighborhood after dark. A person who is street-smart would know better than to visit that neighborhood after dark but might not score so well on an IQ test.
Step-by-step explanation:
Answer:
Step-by-step explanation:
To calculate the value of the standard deviation in this equation, we must use Z-scores, therefore we are assuming that the distribution is regular.
At the twentieth percentile of a regular distribution, the z-score is -2.88. Using this information we can reverse-engineer the z-score calculation equation, [tex]z=\frac{n - x'}{s_{x} }[/tex]. x' being the mean of 100, n being the value of 85, z being the z score of -2.88 and s base x being the standard deviation.
[tex]-2.88=\frac{85-100}{s_{x}}[/tex].
The standard deviation is equivalent to 5.2083
