1. Do Now Turn in Theophylline Clinical Trial HW Safety Quiz
Today: Accuracy vs. Precision. Finish for HW

2. Accuracy vs. Precision

3. Accuracy vs. Precision
Accuracy=how close the results are to the correct answer (Bull’s eye!)
To determine accuracy, we look at the average of our results.
Precision= how often the same results are measured/obtained
To determine precision, we look at the consistency of our results.

4. AVERAGE
ACCURATE NO

5. each trial/measurement
precise NO

6. Accuracy vs. Precision Practice
YES
YES

7. Accuracy vs. Precision Practice
4.67 NO 99
YES
YES NO

8. Percent Error
A quantitative way we can look at the accuracy of a set of data if the true value is known
For this class, we’ll say the data is accurate if the percent error is less than 5%

9. The freezing point of water is 273. 2 K, but it was measured at 250
The freezing point of water is K, but it was measured at K. What is the percentage error?
Subtract first,
then divide,
then multiply by 100
×100%
250.1− ×100%=
=0.084×100%
=𝟖.𝟒%
NOT ACCURATE

10. Percent Error Practice
2) 4.49 % 3) 888% 4) 3.88%