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Test scores have a mean of 100 and a standard diviation of 20 what is the relative frequency of scores under 120?
Wiki User
∙ 10y ago
Approx 84%.
Wiki User
∙ 10y ago
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How can you convert standard scores to percentiles?
You need to use a table of standard scores.
Assume that aset of test scores is normally distributed with a mean of 100 and a standard deviation of 20 use the 68-95-99?
68% of the scores are within 1 standard deviation of the mean -80, 120 95% of the scores are within 2 standard deviations of the mean -60, 140 99.7% of the scores are within 3 standard deviations of the mean -40, 180
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.
If a test score of 83 was transformed into a standard score of -1.5 and the standard deviation of the scores was 4 what is the mean?
78
What is the value of the estimated standard error for the following set of d-scores?
1,7,1
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.
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.
How can you convert standard scores to percentiles?
You need to use a table of standard scores.
If the standard deviation of 10 scores is 0?
If the standard deviation of 10 scores is zero, then all scores are the same.
If standard deviation of 10 scores is 0?
All the scores are equal
Advantages and disadvantages of grouped frequency distribution?
The advantage of a grouped frequency distribution is that it is small enough for you to get a pretty good idea at a glance how the scores are distributed. The disadvantage is that you are lumping scores together, thus losing some of the information in the original scores.
What is simple frequency distribution?
Simple frequency distribution is a method of organizing large data sets into more easily interpreted sets. An example is organizing sample test scores by the individual scores.
Under what circumstances should you use a grouped frequency distribution instead of a regular frequency distibution?
You should use a grouped frequency when you have a wide range of scores.
The following frequency distribution analyzes the scores on a math test. Find the class midpoint of scores interval 40 and ndash59.?
49.0
Assume that aset of test scores is normally distributed with a mean of 100 and a standard deviation of 20 use the 68-95-99?
68% of the scores are within 1 standard deviation of the mean -80, 120 95% of the scores are within 2 standard deviations of the mean -60, 140 99.7% of the scores are within 3 standard deviations of the mean -40, 180
What is a negative frequency distribution?
If most the population has many high scores, the distribution is negatively skewed. If most have many low scores, it is positively skewed
If a sample of n 15 scores has been organized in a grouped frequency distribution table it is possible to obtain a list of all 15 scores from the table?
true
