Answer:

161

Step-by-step explanation:

Step #1: Just add the numbers in the ratio "1:4:7"

(then the sum is 12)

Step #2: then divide the 276 to the 12

(so, every 1 is equivalent to the 23)

Step #3: multiply the 23 to the numbers in the ratio

1(23) = 23

4(23) =92

7(23) = 161

Step #4: Then check the answer if it is correct by adding it

23+92+161 =276

1:4:7 is equivalent to 23+92+161

so to answer the question,

the value of the third number in the ratio is 161

Hope it helps.