The scores of eighth-grade students in a math test are normally distributed with a mean of 57.5 and a standard deviation of 6.5. From this data, we can conclude that 68% of the students received scores between and .

Question

The scores of eighth-grade students in a math test are normally distributed with a mean of 57.5 and a standard deviation of 6.5. From this data, we can conclude that 68% of the students received scores between  and .

anonymous · Answer

The standard deviation is a measure of how spread out numbers are.

Its symbol is  $$\sigma$$ (the greek letter sigma)

The formula is easy: it is the square root of the variance.

anonymous · Answer

Do you know what a variance is?

anonymous · Answer

no

anonymous · Answer

The variance is basically the average of the squared differences from the mean.

To calculate the variance follow these steps:

Work out the mean (the simple average of the numbers)
Then for each number: subtract the mean and square the result (the squared difference).
Then work out the average of those squared differences.

anonymous · Answer

btw, do u have any answer choices?

anonymous · Answer

ok thank you!