What is the average IQ for a normally distributed population of individuals?

Based on the 68-95-99.7 Rule, approximately 68\% of the individuals in the population have an IQ between 85 and 115. Values in this particular interval are the most frequent. Approximately 95\% of the population has IQ scores between 70 and 130. Approximately 99.7\% of the population has IQ scores between 55 and 145.

Does human intelligence follow a normal distribution?

Intelligence test scores follow an approximately normal distribution, meaning that most people score near the middle of the distribution of scores and that scores drop off fairly rapidly in frequency as one moves in either direction from the centre.

What is the probability that a person has an IQ score greater than 100?

50\%
The probability that a person has an IQ score greater than 100 is 50\%.

Why would a distribution be normal?

Normal distribution, also known as the Gaussian distribution, is a probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean. In graph form, normal distribution will appear as a bell curve.

What is the normal distribution of IQ scores?

An IQ test score is calculated based on a norm group with an average score of 100 and a standard deviation of 15. The standard deviation is a measure of spread, in this case of IQ scores. A standard devation of 15 means 68\% of the norm group has scored between 85 (100 – 15) and 115 (100 + 15).

What three factors do most reputable intelligence test have in common?

Reputable tests have three factors in common. They are all standardized, valid, and reliable.

Is the normal distribution accurate?

It is the most important probability distribution in statistics because it accurately describes the distribution of values for many natural phenomena. For example, heights, blood pressure, measurement error, and IQ scores follow the normal distribution.

What is the distribution of IQ scores?

IQ score ranges

IQ scale	Interpretation of IQ score	\% of population
111-120	Above average intelligence	15.7\%
90-110	Average intelligence	51.6\%
80-89	Below average intelligence	15.7\%
70-79	Cognitively impaired	6.4\%

Why is the normal distribution so important in statistics?

As with any probability distribution, the normal distribution describes how the values of a variable are distributed. It is the most important probability distribution in statistics because it accurately describes the distribution of values for many natural phenomena.

When considering a normal distribution of scores what percentage of scores is equal to or below the mean?

In a normal distribution, approximately 68\% of scores are within 1 standard deviation of the mean; half of these (34\%) are above the mean, and the other half are below the mean.