Question

The water level as a river recedes after a flood is measured at regular intervals, and its height relative to normal, in inches, follows the sequence below. If the sequence continues, what do you expect the 7th measurement to be? 16, 9, 2, –5, ...,

Answer 1

7th measurement = -26

Explanation:

The sequence is 16, 9, 2, –5, ...,

First term( a)= 16

Second term=9

Common difference (d) = 9-16

Common difference= -7

The sequence is a arithmetic progression

For AP's ,the terms formula is

Term(n) = a + (n-1)d

Where n represent the term to be found

In this case,we Are looking for the 7th term , so n= 7

Term(7) = 16+ (7-1)-7

Term(7)= 16 +6(-7).

Term (7) = 16-42

Term(7) = -26

7th term =-26