Final answer:
To find the critical value for c=0.99 and n=10, first calculate the degrees of freedom (df=9). Then use a t-distribution table or a statistical calculator function like invT to determine the exact critical t value.
Step-by-step explanation:
To find the critical value tc for a confidence level of c=0.99 and a sample size of n=10, we first determine the degrees of freedom which is df = n - 1 = 10 - 1 = 9. With these degrees of freedom, we refer to the t-distribution table or use a calculator function like invT to find the critical t value for a two-tailed test corresponding to the 99% confidence level.
Since the provided information does not include the exact value for a 99% confidence level and 9 degrees of freedom, let's assume we are looking for the closest value from the options given. The values in the options provided, 3.25 and 2.76, would both be reasonable considerations, but one needs to consult the exact t-distribution table or a calculator to find the precise critical value.