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Finding the Fourth Proportional to 761.79, 1,142.48 and 391.35

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Solution

The fourth proportional to 761.79, 1,142.48 and 391.35 is: 586.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    761.79 : 1,142.48 = 391.35 : x
  2. Step 2: Convert to fraction form
    761.79/1,142.48 = 391.35/x
  3. Step 3: Cross multiply
    761.79x = 1,142.48 × 391.35
  4. Step 4: Simplify right side
    761.79x = 447,107.59
  5. Step 5: Solve for x
    x = 447,107.59/761.79
  6. Step 6: Final answer
    x = 586.92

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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.