Home / 1,285.85-1,929.12-408.38

Finding the Fourth Proportional to 1,285.85, 1,929.12 and 408.38

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Solution

The fourth proportional to 1,285.85, 1,929.12 and 408.38 is: 612.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,285.85 : 1,929.12 = 408.38 : x
  2. Step 2: Convert to fraction form
    1,285.85/1,929.12 = 408.38/x
  3. Step 3: Cross multiply
    1,285.85x = 1,929.12 × 408.38
  4. Step 4: Simplify right side
    1,285.85x = 787,802.85
  5. Step 5: Solve for x
    x = 787,802.85/1,285.85
  6. Step 6: Final answer
    x = 612.67

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.