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Finding the Fourth Proportional to 856.47, 1,284.71 and 666.39

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Solution

The fourth proportional to 856.47, 1,284.71 and 666.39 is: 999.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.47 : 1,284.71 = 666.39 : x
  2. Step 2: Convert to fraction form
    856.47/1,284.71 = 666.39/x
  3. Step 3: Cross multiply
    856.47x = 1,284.71 × 666.39
  4. Step 4: Simplify right side
    856.47x = 856,114.56
  5. Step 5: Solve for x
    x = 856,114.56/856.47
  6. Step 6: Final answer
    x = 999.59

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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.