Question

if 4,a,b,28 are in arithmetic progression then the value of b is​

Answer 1

Answer:

4 ,a ,b,28 are in A.P. then their common difference is 8 then value of b is 20

Answer 2

The value of b is 20.

Given:

4, a,b, and 28 are in arithmetic progression.

To Find:

The value of b.

Solution:

To find the value of b we will follow the following steps:

As we know,

The formula for finding the nth term of the arithmetic progression series is

x = a + (n-1)d

x is the nth term, a is the first term and d is the difference between the terms.

Now,

Putting values for the 4th term which is 28 and calculate the value of d.

We get,

28 = 4 + (4-1)d

24 = 3d

$d = \frac{24}{3} = 8$

The difference between the two consecutive terms is 8.

a - 4 = b - a = 28 - b = 8

So,

The difference between the 3rd and 4th terms is also 8.

28 - b = 8

b = 28 - 8 = 20.

Henceforth, the value of b is 20.