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Finding the Fourth Proportional to 759.38, 1,139.37 and 485.39

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Solution

The fourth proportional to 759.38, 1,139.37 and 485.39 is: 728.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    759.38 : 1,139.37 = 485.39 : x
  2. Step 2: Convert to fraction form
    759.38/1,139.37 = 485.39/x
  3. Step 3: Cross multiply
    759.38x = 1,139.37 × 485.39
  4. Step 4: Simplify right side
    759.38x = 553,039.83
  5. Step 5: Solve for x
    x = 553,039.83/759.38
  6. Step 6: Final answer
    x = 728.28

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.