Answer:
+2.718
Step-by-step explanation:
from the question,
the sample size is 12
therefore the degree of freedom,
df = 12 - 1
= 11
alpha = 1 - 0.98
= 0.02
this is because the confidence level is 98%
under the t distribution table, a degree of freedom of 11 and 0.02 alpha level = 2.718
the critical value t* = 2.718
I hope this helps!