find the common difference if the first term of an arithmetic sequence is 2 and the 11th term is 9.5

Answer 1

common difference = 0.75 or 3/4

an = a1 + (n-1)d where d is the common difference

a11 = a1 + (11-1)d

9.5 = 2 + 10d

10d = 7.5

d = 7.5/10 = 0.75