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Finding the Fourth Proportional to 418.59, 577.33 and 390.65

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Solution

The fourth proportional to 418.59, 577.33 and 390.65 is: 538.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.59 : 577.33 = 390.65 : x
  2. Step 2: Convert to fraction form
    418.59/577.33 = 390.65/x
  3. Step 3: Cross multiply
    418.59x = 577.33 × 390.65
  4. Step 4: Simplify right side
    418.59x = 225,531.54
  5. Step 5: Solve for x
    x = 225,531.54/418.59
  6. Step 6: Final answer
    x = 538.79

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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.