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Finding the Fourth Proportional to 865.81, 1,298.80 and 345.69

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Solution

The fourth proportional to 865.81, 1,298.80 and 345.69 is: 518.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.81 : 1,298.80 = 345.69 : x
  2. Step 2: Convert to fraction form
    865.81/1,298.80 = 345.69/x
  3. Step 3: Cross multiply
    865.81x = 1,298.80 × 345.69
  4. Step 4: Simplify right side
    865.81x = 448,982.17
  5. Step 5: Solve for x
    x = 448,982.17/865.81
  6. Step 6: Final answer
    x = 518.57

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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.