Consumer preferences have been observed in a situation for which the standard error is known. Find the appropriate t value from the t table to use for each of the following confidence interval calculations:
a. Two-sided 95% confidence.
b. Two-sided 99% confidence.
c. Two-sided 99.9% confidence.
d. Two-sided 90% confidence.
e. One-sided 95% confidence.
f. One-sided 99% confidence.