Use the data to answer the question.

\begin{tabular}{|l|l|}
\hline
\multicolumn{2}{|c|}{Correct Value: 23.0} \\
\hline
Experiment 1 & 17.8 \\
\hline
Experiment 2 & 18.0 \\
\hline
Experiment 3 & 17.9 \\
\hline
Experiment 4 & 18.2 \\
\hline
\end{tabular}

Which best describes the data?

A. They are accurate and reproducible.
B. They are accurate but not reproducible.
C. They are precise and reproducible.
D. They are precise but not reproducible.



Answer :

To determine the best description for the given experimental data, we need to evaluate two main aspects: accuracy and reproducibility. Here’s the step-by-step solution:

1. List the given data and the correct value:
- Correct value: [tex]\( 23.0 \)[/tex]
- Experiment values: [tex]\( 17.8, 18.0, 17.9, 18.2 \)[/tex]

2. Calculate the mean (average) of the experiment values:
[tex]\[ \text{Mean} = \frac{17.8 + 18.0 + 17.9 + 18.2}{4} = 17.975 \][/tex]

3. Determine Accuracy:
- Accuracy is judged by how close the mean of the experiment values is to the correct value.
- The mean is [tex]\( 17.975 \)[/tex], and the correct value is [tex]\( 23.0 \)[/tex].
- Since [tex]\( 17.975 \)[/tex] is more than 5 units away from [tex]\( 23.0 \)[/tex], the experiments are not accurate.

4. Determine Reproducibility (Precision):
- Reproducibility can be assessed by calculating the standard deviation of the experiments.
- The standard deviation of the experiment values is [tex]\( 0.1479 \)[/tex]. Given a low standard deviation, the experiment results are closely clustered around the mean, indicating that the experiments are reproducible.

5. Conclusion:
- Based on the steps above, the mean indicates that the experiments are not close to the correct value, making them not accurate.
- The low standard deviation suggests that the experiments are reproducible.

So, the best description for the data is:

"They are precise and reproducible."