1. **State the problem:** We are given the numbers $0.19 \times 10^4$, $0.019 \times 10^3$, $1.9 \times 10^2$, and $10.9 \times 10^3$. We want to express each number in standard decimal form to compare or analyze them. 2. **Recall the rule:** Multiplying by $10^n$ means moving the decimal point $n$ places to the right if $n$ is positive. 3. **Convert each number:** - $0.19 \times 10^4 = 0.19 \times 10000 = 1900$ - $0.019 \times 10^3 = 0.019 \times 1000 = 19$ - $1.9 \times 10^2 = 1.9 \times 100 = 190$ - $10.9 \times 10^3 = 10.9 \times 1000 = 10900$ 4. **Summary:** The numbers in decimal form are $1900$, $19$, $190$, and $10900$ respectively. This conversion helps in understanding the magnitude of each number clearly.