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Finding the Fourth Proportional to 620.40, 855.72 and 542.64

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Solution

The fourth proportional to 620.40, 855.72 and 542.64 is: 748.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.40 : 855.72 = 542.64 : x
  2. Step 2: Convert to fraction form
    620.40/855.72 = 542.64/x
  3. Step 3: Cross multiply
    620.40x = 855.72 × 542.64
  4. Step 4: Simplify right side
    620.40x = 464,347.90
  5. Step 5: Solve for x
    x = 464,347.90/620.40
  6. Step 6: Final answer
    x = 748.47

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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.