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Finding the Fourth Proportional to 538.80, 743.40 and 391.68

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Solution

The fourth proportional to 538.80, 743.40 and 391.68 is: 540.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    538.80 : 743.40 = 391.68 : x
  2. Step 2: Convert to fraction form
    538.80/743.40 = 391.68/x
  3. Step 3: Cross multiply
    538.80x = 743.40 × 391.68
  4. Step 4: Simplify right side
    538.80x = 291,174.91
  5. Step 5: Solve for x
    x = 291,174.91/538.80
  6. Step 6: Final answer
    x = 540.41

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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.