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Finding the Fourth Proportional to 656.09, 905.43 and 420.23

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Solution

The fourth proportional to 656.09, 905.43 and 420.23 is: 579.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.09 : 905.43 = 420.23 : x
  2. Step 2: Convert to fraction form
    656.09/905.43 = 420.23/x
  3. Step 3: Cross multiply
    656.09x = 905.43 × 420.23
  4. Step 4: Simplify right side
    656.09x = 380,489.54
  5. Step 5: Solve for x
    x = 380,489.54/656.09
  6. Step 6: Final answer
    x = 579.94

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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.