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Finding the Fourth Proportional to 390.60, 547.80 and 390.60

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Solution

The fourth proportional to 390.60, 547.80 and 390.60 is: 547.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.60 : 547.80 = 390.60 : x
  2. Step 2: Convert to fraction form
    390.60/547.80 = 390.60/x
  3. Step 3: Cross multiply
    390.60x = 547.80 × 390.60
  4. Step 4: Simplify right side
    390.60x = 213,970.68
  5. Step 5: Solve for x
    x = 213,970.68/390.60
  6. Step 6: Final answer
    x = 547.80

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.