Example question about rounding up in standard deviation problem

[shadow crypt]

In this types of questions where I need to get the number of scores in the range of 1 standard deviation of the mean,the calculated answer by doing 68% multiplied by the number of available scores gives me an answer of 4.02,while the ogical question by seeing the scores that lie in the range it gives 5,so why do we round up the 4.02 into 5?I know his question is stupid but I honestly don't know

[wispy trellis]

1. Wait patiently for a helper to come along.
2. Once someone helps you, say thank you and close the thread with:

+close

3. Feel free to nominate the person for helper of the week in #helper-nominations

[shadow crypt]

Example question about rounding up in standard deviation problem

[hexed oyster]

First, let's find the sample mean.
<X> = (100 + 85 + 55 + 95 + 75 + 100)/6 = 85
Supposing that the true mean is about the same as the sample mean, we get (μ - σ, μ + σ) = (85 - 16, 85 + 16) = (69, 101). So, count how many of the scores fall into that interval.

[shadow crypt]

The problem is if this question contained a large number of scores that they didn't give me but they gave me the mean and SD,The rule is that 68% lie in the range of 1 SD away from the mean,so we multiply 68% by the total number of scores,if the result is a decimal should I round up or down?

[hexed oyster]

No. We are dealing with a sample here, not with the distribution. So, no need for that.

So, just count how many scores are in the interval.

[shadow crypt]

And if they didn't give me their individual scores?

[hexed oyster]

Then the question would be "if there were 6 students taking the exam, estimate how many students would get a score within one SD from the mean".
So, while in this case we can just count and say with certainty, in that case we would have to estimate.

[shadow crypt]

+close