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Finding the Fourth Proportional to 528.40, 729.18 and 318.48

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Solution

The fourth proportional to 528.40, 729.18 and 318.48 is: 439.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    528.40 : 729.18 = 318.48 : x
  2. Step 2: Convert to fraction form
    528.40/729.18 = 318.48/x
  3. Step 3: Cross multiply
    528.40x = 729.18 × 318.48
  4. Step 4: Simplify right side
    528.40x = 232,229.25
  5. Step 5: Solve for x
    x = 232,229.25/528.40
  6. Step 6: Final answer
    x = 439.50

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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.