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, ...,

7th measurement = -26

Step-by-step 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

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.