# Question: Units of Standard Deviation

## Comment on Units of Standard Deviation

### When the question asks for

When the question asks for the numbers that are more than half the unit of standard deviation, would not it be the numbers that are greater than 6.9 ? Why do choose the numbers that fall below 6.9? Please reply. Thanks. ### The question is asking us to

The question is asking us to identify all values that are more than 0.5 units of standard deviation BELOW the mean.

0.5 units of standard deviation BELOW the mean = 9 - (0.5)(4.2) = 6.9

0.6 units of standard deviation BELOW the mean = 9 - (0.6)(4.2) = 6.48. This means that 6.48 is more than 0.5 units of standard deviation BELOW the mean

Likewise, 0.7 units of standard deviation BELOW the mean = 9 - (0.7)(4.2) = 6.06. This means that 6.06 is more than 0.5 units of standard deviation BELOW the mean

Does that help?

### So, What happen with numbers

So, What happen with numbers 14 and 18 are? Why are they not included as part of the answer ? if they are numbers > 0.5 units of SD in the right side. ### The question does not ask us

The question does not ask us to identify values that are more than 0.5 units of SD AWAY from the mean. It asks us to identify values that are more than 0.5 units of SD BELOW (less than) the mean

### Thanks so much. Probability,

Thanks so much. Probability, I didn't pay attention to the word "below". So, Everything is clear now. ### im really amazed with ur

im really amazed with ur videos and prompt replies ...thnx a lot. ### Hi! Can you use a proportion

Hi! Can you use a proportion for the units of SD. For example, 1 unit of SD/4.2 SD = 0.5 units of SD/x SD to get 2.1? Most definitely!

### Great exercise!. At first I

Great exercise!. At first I answered 6, but those are the number below the mean. The answer ask for the numbers 0.5 units of SD below of the mean.

### how do you determine 6 as the

how do you determine 6 as the answer by looking at
7.6 below , 12, mean 16.4 above. ### Tuttiam52 isn't saying that

Tuttiam52 isn't saying that the correct answer is 6.

With "Units of Standard Deviation (SD)" questions, we often look at units of SD ABOVE the mean and units of SD BELOW the mean.

This question asks for 0.5 units of SD BELOW the mean.
So, we must SUBTRACT 2.1 from the 9 (the mean)

For more on this see: https://www.greenlighttestprep.com/module/gre-statistics/video/808

### Thank you so much for the

Thank you so much for the amazing videos sir. Being an educator I have an immense respect towards the profession and you are really an inspiration for me.. ### Thanks for the kind words,

Thanks for the kind words, Reetika!

### Hi Brent,

Hi Brent,

Thank you very much for this explanation!
I have a question, if they would ask us to find all values that are 0.5 standard deviation below the mean, meaning between 6.9 and 9.
The values are like this: 7,7,7,8,8,8
Should we include 9 as well or not? Thanks ### If the question asked "find

If the question asked "find all values that are 0.5 standard deviations BELOW the mean", then the ONLY value that satisfies that condition is 6.9, since 6.9 is 0.5 standard deviations below the mean.

If the question asked "find all values that are LESS THAN 0.5 standard deviations BELOW the mean", then the values that satisfy that condition are 7,7,7,8,8,and 9.
9 work because 9 is 0 standard deviations below the mean.

Cheers,
Brent

### Thanks Brent now it is clear!

Thanks Brent now it is clear!