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Finding the Fourth Proportional to 657.22, 985.20 and 286.78

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Solution

The fourth proportional to 657.22, 985.20 and 286.78 is: 429.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.22 : 985.20 = 286.78 : x
  2. Step 2: Convert to fraction form
    657.22/985.20 = 286.78/x
  3. Step 3: Cross multiply
    657.22x = 985.20 × 286.78
  4. Step 4: Simplify right side
    657.22x = 282,535.66
  5. Step 5: Solve for x
    x = 282,535.66/657.22
  6. Step 6: Final answer
    x = 429.90

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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.