Q:

What is the missing value in the following arithmetic sequence? n 1 2 3 4 5 an 2 3.8 5.6 9.2 7.1 7.2 7.4 7.5

Accepted Solution

A:
1. You have an arithmetic sequense: 2, 3.8, 5.6, 9.2. Here \(a_1=2, \\ a_2=3.8\), then \(d=a_2-a_1=3.8-2=1.8\).Adding d to the second term you receive the third term: \(a_3=3.8+1.8=5.6\).Adding d to the third term you receive the fourth term: \(a_4=5.6+1.8=7.4\).Adding d to the fourth term you receive the fih term:\(a_5=7.4+1.8=9.2\).The fourth term \(a_4=7.4\) is missed in this arithmetic sequence.2. Now you have an arithmetic sequense: 7.1, 7.2, 7.4, 7.5.\(a_1=7.1 \\ a_2=7.2,Β \text{} so {} d=a_2-a_1=0.1 \\ a_3=7.2+0.1=7.3 \\ a_4=7.3+0.1=7.4 \\ a_5=7.4+0.1=7.5\).The third term \(a_3=7.3\) is missed in this arithmetic sequence.