Answer:
Critical value t-score=2.701.
Step-by-step explanation:
When we calculate a confidence interval with an unknown population standard deviation, we estimate it from the sample standard deviation and use the t-score instead of the z-score.
The critical value for t depends on the level of confidence and the degrees of freedom.
If the sample size is 42, the degrees of freedom are:
[tex]df=n-1=42-1=41[/tex]
For a confidence level of 99% and 41 degrees of freedom, the critical value of t is t=2.701.
