Which property does the following statement illustrate? (a+b)c = (b+a)c A: associative
B: Commutative
C: Identity
D: None

Find the t-value(s) for each of the following cases. round your answers to 3 decimals places. enter negative values as negative number. a. upper tail area of .025 with 12 degrees of freedom is b. lower tail area of .005 with 55 degrees of freedom is c. upper tail area of .01 with 30 degrees of freedom is d. where 98% of the area falls between these two t-values with 25 degrees of freedom e. where 95% of the area falls between these two t-values with 45 degrees of freedom