Home / 1,129.18-1,557.39-815.61

Finding the Fourth Proportional to 1,129.18, 1,557.39 and 815.61

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Solution

The fourth proportional to 1,129.18, 1,557.39 and 815.61 is: 1,124.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,129.18 : 1,557.39 = 815.61 : x
  2. Step 2: Convert to fraction form
    1,129.18/1,557.39 = 815.61/x
  3. Step 3: Cross multiply
    1,129.18x = 1,557.39 × 815.61
  4. Step 4: Simplify right side
    1,129.18x = 1,270,218.78
  5. Step 5: Solve for x
    x = 1,270,218.78/1,129.18
  6. Step 6: Final answer
    x = 1,124.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.