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Finding the Fourth Proportional to 528.72, 729 and 390.48

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Solution

The fourth proportional to 528.72, 729 and 390.48 is: 538.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    528.72 : 729 = 390.48 : x
  2. Step 2: Convert to fraction form
    528.72/729 = 390.48/x
  3. Step 3: Cross multiply
    528.72x = 729 × 390.48
  4. Step 4: Simplify right side
    528.72x = 284,659.92
  5. Step 5: Solve for x
    x = 284,659.92/528.72
  6. Step 6: Final answer
    x = 538.39

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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.