Final answer:
The calculated t value of 1.729 is right on the threshold of rejection or acceptance, indicating borderline significance.
Step-by-step explanation:
The statement means that the calculated t value of 1.729 is right on the threshold of rejection or acceptance at a confidence level of more than 90% with 19 degrees of freedom. This indicates that the difference observed in the sample is borderline significant.
If the calculated t value was slightly higher, it would have exceeded the critical value and the null hypothesis would have been rejected.
Similarly, if the calculated t value was slightly lower, it would have fallen below the critical value and the null hypothesis would have been accepted.