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1 The average of the squared deviation scores from a distribution mean?
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∙ 15y ago
Variance
Wiki User
∙ 15y ago
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What does standard deviation show us about a set of scores?
Standard Deviation tells you how spread out the set of scores are with respects to the mean. It measures the variability of the data. A small standard deviation implies that the data is close to the mean/average (+ or - a small range); the larger the standard deviation the more dispersed the data is from the mean.
Why is the standard deviation one?
The standard deviation provides in indication of what proportion of the entire distribution of the sample falls within a certain distance from the mean or average for that sample. If your data falls on a normal (or bell shaped) distribution, a SD of 1 indicates that about 68% of your data points (scores or whatever else) fall within 1 point (plus or minus) of the average (mean) of the data, and 95% fall within 2 points.
Why in a normal distribution the distribution will be less spread out when the standard diviation of the raw scores is small?
The standard deviation (SD) is a measure of spread so small sd = small spread. So the above is true for any distribution, not just the Normal.
How do you find the semi-interquartile range with only the mean and standard deviation?
In general, you cannot. If the distribution can be assumed to be Gaussian [Normal] then you could use z-scores.
Why standard deviation scores over mean deviation as a more accurate measures of dispersion?
It is not. And that is because the mean deviation of ANY variable is 0 and you cannot divide by 0.
What word means the average of the squared deviation scores from a distribution mean?
Variance
The standard deviation is the square root of the average squared deviation of scores from the?
mean
What statistic is the average amount by which the scores in a distribution vary from the mean?
Standard deviation
Is the variance of a group of scores the same as the squared standard deviation?
The standard deviation is defined as the square root of the variance, so the variance is the same as the squared standard deviation.
Is the variance of a group of scores the same as the sum of the squared deviations or the average of the squared deviations?
Given a set of n scores, the variance is sum of the squared deviation divided by n or n-1. We divide by n for the population and n-1 for the sample.
The mean of a distribution of scores is the?
The mean of a distribution of scores is the average.
What is the mean and standard deviation of a distribution of T-scores?
T-scores have a mean of 50 and a standard deviation of 10. These values are fixed and do not change regardless of the distribution of T-scores.
What percent of the scores in a normal distribution will fall within one standard deviation?
It is 68.3%
How many of scores will be within 1 standard deviation of the population mean?
Assuming a normal distribution 68 % of the data samples will be with 1 standard deviation of the mean.
Will increasing the frequency of scores in the tails of a distribution effect the standard deviation How or Why?
Yes. It will increase the standard deviation. You are increasing the number of events that are further away from the mean, and the standard deviation is a measure of how far away the events are from the mean.
If the standard deviation of 10 scores is 0?
If the standard deviation of 10 scores is zero, then all scores are the same.
What is quartile deviational?
Quartile Deviation (QD)The quartile deviation is half the difference between the upper and lower quartiles in a distribution. It is a measure of the spread through the middle half of a distribution. It can be useful because it is not influenced by extremely high or extremely low scores. Quartile Deviation is an ordinal statistic and is most often used in conjunction with the median.why we calculating quartile deviation?
