Homework SourseA researcher has developed a new analytical method to determ
A researcher has developed a new analytical method to determine the percent by mass iron in solids. To test the new method, the researcher purchases a standard reference material sample that is 2.85% iron by mass. Analysis of the iron standard returns values of 2.75%, 2.89%, 2.77%, 2.81%, and 2.87%. Are the results of the new method significantly different (at the 95% confidence interval) from the standard reference sample? Consult your textbook Table 4-2 for Student’s t values.
Solution
Null hypotheis : The method is not significantly different than the standard reference sample
Alternative hypothesis: The method is significantly different
Since statistic value is less than significant value , donot reject the null hypothesis.
Hence conclude that the results of the new method is not significantly different from the standard referece sample
| t Test for Hypothesis of the Mean | |
| Data | |
| Null Hypothesis m= | 2.85 |
| Level of Significance | 0.05 |
| Sample Size | 5 |
| Sample Mean | 2.818 |
| Sample Standard Deviation | 0.060991803 |
| Intermediate Calculations | |
| Standard Error of the Mean | 0.027276363 |
| Degrees of Freedom | 4 |
| t Test Statistic | -1.17317692 |
| Two-Tail Test | |
| Lower Critical Value | -2.776445105 |
| Upper Critical Value | 2.776445105 |
| p-Value | 0.305816808 |
| Do not reject the null hypothesis |
