What does a 13 standard deviation mean?
Thus, depending on the design of the test, a score of, say, 13 can’t be directly compared between tests. On the fourth grade test, for instance, a score of 13 is equivalent to the 84th percentile (one s.d. from the mean), whereas a score of 13 is at the 98th percentile in fifth grade (two s.d.).
What is the standard deviation of the data 10 28 13?
Hence, ∑xi = 10 + 28 + 13 + 18 + 29 + 30 + 22 + 23 + 25 + 32 = 230. Hence, Mean, μ = 230/10 = 23. Hence, the standard deviation is 7.
How do you find the middle 50 of a normal distribution?
The middle 50% is usually calculated by subtracting the first quartile (the 25% mark) from the third quartile (the 75% mark): Middle 50% = Q3 – Q1.
What is a large standard deviation?
A large standard deviation indicates that there is a lot of variance in the observed data around the mean. This indicates that the data observed is quite spread out. A small or low standard deviation would indicate instead that much of the data observed is clustered tightly around the mean.
What is a standard deviation in statistics?
A standard deviation (or σ) is a measure of how dispersed the data is in relation to the mean. Low standard deviation means data are clustered around the mean, and high standard deviation indicates data are more spread out.
What is the standard deviation of 35?
Under general normality assumptions, 95% of the scores are within 2 standard deviations of the mean. For example, if the average score of a data set is 250 and the standard deviation is 35 it means that 95% of the scores in this data set fall between 180 and 320.
What is the middle 50 percent?
Middle 50% means half of the students we admitted scored within the listed range. It also means 25% of the students we admitted had scores below the range and 25% had scores above.
What is the range covered by the middle 50% of the ages?
inter-quartile range (IQR)
Another measure of spread is the inter-quartile range (IQR), which is the range covered by the middle 50% of the data.