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Finding the Fourth Proportional to 656.28, 905.54 and 390.62

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Solution

The fourth proportional to 656.28, 905.54 and 390.62 is: 538.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.28 : 905.54 = 390.62 : x
  2. Step 2: Convert to fraction form
    656.28/905.54 = 390.62/x
  3. Step 3: Cross multiply
    656.28x = 905.54 × 390.62
  4. Step 4: Simplify right side
    656.28x = 353,722.03
  5. Step 5: Solve for x
    x = 353,722.03/656.28
  6. Step 6: Final answer
    x = 538.98

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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.