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Finding the Fourth Proportional to 655.98, 905.08 and 390.49

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Solution

The fourth proportional to 655.98, 905.08 and 390.49 is: 538.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    655.98 : 905.08 = 390.49 : x
  2. Step 2: Convert to fraction form
    655.98/905.08 = 390.49/x
  3. Step 3: Cross multiply
    655.98x = 905.08 × 390.49
  4. Step 4: Simplify right side
    655.98x = 353,424.69
  5. Step 5: Solve for x
    x = 353,424.69/655.98
  6. Step 6: Final answer
    x = 538.77

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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.