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Finding the Fourth Proportional to 528.45, 729.21 and 318.75

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Solution

The fourth proportional to 528.45, 729.21 and 318.75 is: 439.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    528.45 : 729.21 = 318.75 : x
  2. Step 2: Convert to fraction form
    528.45/729.21 = 318.75/x
  3. Step 3: Cross multiply
    528.45x = 729.21 × 318.75
  4. Step 4: Simplify right side
    528.45x = 232,435.69
  5. Step 5: Solve for x
    x = 232,435.69/528.45
  6. Step 6: Final answer
    x = 439.84

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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.