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Finding the Fourth Proportional to 520.78, 718.58 and 405.22

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Solution

The fourth proportional to 520.78, 718.58 and 405.22 is: 559.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.78 : 718.58 = 405.22 : x
  2. Step 2: Convert to fraction form
    520.78/718.58 = 405.22/x
  3. Step 3: Cross multiply
    520.78x = 718.58 × 405.22
  4. Step 4: Simplify right side
    520.78x = 291,182.99
  5. Step 5: Solve for x
    x = 291,182.99/520.78
  6. Step 6: Final answer
    x = 559.13

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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.