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Finding the Fourth Proportional to 719.55, 1,078.86 and 257.31

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Solution

The fourth proportional to 719.55, 1,078.86 and 257.31 is: 385.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    719.55 : 1,078.86 = 257.31 : x
  2. Step 2: Convert to fraction form
    719.55/1,078.86 = 257.31/x
  3. Step 3: Cross multiply
    719.55x = 1,078.86 × 257.31
  4. Step 4: Simplify right side
    719.55x = 277,601.47
  5. Step 5: Solve for x
    x = 277,601.47/719.55
  6. Step 6: Final answer
    x = 385.80

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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.