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Finding the Fourth Proportional to 758.89, 1,138.98 and 642.49

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Solution

The fourth proportional to 758.89, 1,138.98 and 642.49 is: 964.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    758.89 : 1,138.98 = 642.49 : x
  2. Step 2: Convert to fraction form
    758.89/1,138.98 = 642.49/x
  3. Step 3: Cross multiply
    758.89x = 1,138.98 × 642.49
  4. Step 4: Simplify right side
    758.89x = 731,783.26
  5. Step 5: Solve for x
    x = 731,783.26/758.89
  6. Step 6: Final answer
    x = 964.28

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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.