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Finding the Fourth Proportional to 656.78, 906.42 and 394.80

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Solution

The fourth proportional to 656.78, 906.42 and 394.80 is: 544.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.78 : 906.42 = 394.80 : x
  2. Step 2: Convert to fraction form
    656.78/906.42 = 394.80/x
  3. Step 3: Cross multiply
    656.78x = 906.42 × 394.80
  4. Step 4: Simplify right side
    656.78x = 357,854.62
  5. Step 5: Solve for x
    x = 357,854.62/656.78
  6. Step 6: Final answer
    x = 544.86

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.