Final answer:
To determine the number of Dollar General Stores in 2007, we calculated the original number before an 87% increase led to 15,370 stores in 2018. Using the equation 1.87x = 15,370 and solving for x, we find there were approximately 8,219 stores in 2007.
Step-by-step explanation:
We are asked to find the number of Dollar General Stores in the United States in 2007 given that there was an 87% increase to 15,370 stores in 2018. To solve this, we'll let the number of stores in 2007 be x. The 87% increase is mathematically represented by the equation x + 0.87x = 15,370, which simplifies to 1.87x = 15,370. Dividing both sides by 1.87, we find x.
Therefore, the calculation will be x = 15,370 / 1.87, which gives us the number of stores in 2007. After performing the division and rounding to the nearest whole number, the answer is x ≈ 8,219 stores.