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Finding the Fourth Proportional to 865.88, 1,298.63 and 345.79

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Solution

The fourth proportional to 865.88, 1,298.63 and 345.79 is: 518.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.88 : 1,298.63 = 345.79 : x
  2. Step 2: Convert to fraction form
    865.88/1,298.63 = 345.79/x
  3. Step 3: Cross multiply
    865.88x = 1,298.63 × 345.79
  4. Step 4: Simplify right side
    865.88x = 449,050.89
  5. Step 5: Solve for x
    x = 449,050.89/865.88
  6. Step 6: Final answer
    x = 518.60

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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.