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Finding the Fourth Proportional to 771.90, 1,157.85 and 339.18

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Solution

The fourth proportional to 771.90, 1,157.85 and 339.18 is: 508.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    771.90 : 1,157.85 = 339.18 : x
  2. Step 2: Convert to fraction form
    771.90/1,157.85 = 339.18/x
  3. Step 3: Cross multiply
    771.90x = 1,157.85 × 339.18
  4. Step 4: Simplify right side
    771.90x = 392,719.56
  5. Step 5: Solve for x
    x = 392,719.56/771.90
  6. Step 6: Final answer
    x = 508.77

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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.