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Finding the Fourth Proportional to 805.64, 1,208.46 and 257.86

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Solution

The fourth proportional to 805.64, 1,208.46 and 257.86 is: 386.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.64 : 1,208.46 = 257.86 : x
  2. Step 2: Convert to fraction form
    805.64/1,208.46 = 257.86/x
  3. Step 3: Cross multiply
    805.64x = 1,208.46 × 257.86
  4. Step 4: Simplify right side
    805.64x = 311,606.16
  5. Step 5: Solve for x
    x = 311,606.16/805.64
  6. Step 6: Final answer
    x = 386.78

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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.