Standard deviation, raw score etc

In summary, the test has a mean of 80, a standard deviation of 5, and a standard error of measurement of 3. The raw score is the same as the observed score, and the true score cannot be determined due to unknown error. The confidence interval at 68% confidence level is from 77 to 83, and the confidence interval at 95% confidence level is from 74.12 to 85.88.
  • #1
saharalynne
1
0
-3 SD -2 SD -1 SD 80 +1SD +2 SD +3 SD
mean
65 70 75 85 90 95

The test has a mean of 80, a standard deviation of 5 and a standard error of measurement of 3.
Information given: Mean = 80 SD = 5 SEM = 3 Jim’s score = 85

I need to know the raw score, observed score, true score, ci for 68 and 95
 
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  • #2
saharalynne said:
-3 SD -2 SD -1 SD 80 +1SD +2 SD +3 SD
mean
65 70 75 85 90 95The test has a mean of 80, a standard deviation of 5 and a standard error of measurement of 3.
Information given: Mean = 80 SD = 5 SEM = 3 Jim’s score = 85

I need to know the raw score, observed score, true score, ci for 68 and 95

Hi saharalynne! Welcome to MHB! (Smile)

The raw score is the original untransformed score, which is the same as the observed score.
We can never know the true score, since what we measure always contains an unknown error.

The confidence interval (CI) at confidence level 68% is the interval from Mean - SEM to Mean + SEM.
And the CI at confidence level 95% is the interval from Mean - 1.96 x SEM to Mean + 1.96 x SEM.

Can you tell what each of those are? (Wondering)
 

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