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Finding the Fourth Proportional to 929.90, 1,394.71 and 409.79

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Solution

The fourth proportional to 929.90, 1,394.71 and 409.79 is: 614.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    929.90 : 1,394.71 = 409.79 : x
  2. Step 2: Convert to fraction form
    929.90/1,394.71 = 409.79/x
  3. Step 3: Cross multiply
    929.90x = 1,394.71 × 409.79
  4. Step 4: Simplify right side
    929.90x = 571,540.67
  5. Step 5: Solve for x
    x = 571,540.67/929.90
  6. Step 6: Final answer
    x = 614.62

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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.