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Finding the Fourth Proportional to 631.60, 946.20 and 387.40

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Solution

The fourth proportional to 631.60, 946.20 and 387.40 is: 580.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.60 : 946.20 = 387.40 : x
  2. Step 2: Convert to fraction form
    631.60/946.20 = 387.40/x
  3. Step 3: Cross multiply
    631.60x = 946.20 × 387.40
  4. Step 4: Simplify right side
    631.60x = 366,557.88
  5. Step 5: Solve for x
    x = 366,557.88/631.60
  6. Step 6: Final answer
    x = 580.36

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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.