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Finding the Fourth Proportional to 523.90, 721.32 and 399.16

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Solution

The fourth proportional to 523.90, 721.32 and 399.16 is: 549.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    523.90 : 721.32 = 399.16 : x
  2. Step 2: Convert to fraction form
    523.90/721.32 = 399.16/x
  3. Step 3: Cross multiply
    523.90x = 721.32 × 399.16
  4. Step 4: Simplify right side
    523.90x = 287,918.48
  5. Step 5: Solve for x
    x = 287,918.48/523.90
  6. Step 6: Final answer
    x = 549.57

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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.