Identifying the Arithmetic Progression
To find out which term of the arithmetic progression 7, 11, 15, 19 a specific number corresponds to, we first need to identify the common difference between consecutive terms. In this case, the common difference is 4, as each number increases by 4 from the previous one.

Finding the Position of the Number
Let's say we are looking for the nth term in the progression. The formula to find the nth term of an arithmetic progression is:
\[ a_n = a_1 + (n-1)d \]
where:
- \( a_n \) is the nth term of the progression
- \( a_1 \) is the first term of the progression
- \( d \) is the common difference between terms
- \( n \) is the position of the term we are trying to find

Substitute the Given Values
In our case, the first term (\( a_1 \)) is 7 and the common difference (\( d \)) is 4. Let's substitute these values into the formula:
\[ 19 = 7 + (n-1)4 \]

Solve for n
Now, we can simplify the equation and solve for n:
\[ 19 = 7 + 4n - 4 \]
\[ 19 = 3 + 4n \]
\[ 16 = 4n \]
\[ n = 4 \]

Conclusion
Therefore, the number 19 corresponds to the 4th term in the arithmetic progression 7, 11, 15, 19.