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Finding the Fourth Proportional to 756.50, 1,043.92 and 420.40

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Solution

The fourth proportional to 756.50, 1,043.92 and 420.40 is: 580.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    756.50 : 1,043.92 = 420.40 : x
  2. Step 2: Convert to fraction form
    756.50/1,043.92 = 420.40/x
  3. Step 3: Cross multiply
    756.50x = 1,043.92 × 420.40
  4. Step 4: Simplify right side
    756.50x = 438,863.97
  5. Step 5: Solve for x
    x = 438,863.97/756.50
  6. Step 6: Final answer
    x = 580.12

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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.