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Finding the Fourth Proportional to 655.99, 905.34 and 390.56

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Solution

The fourth proportional to 655.99, 905.34 and 390.56 is: 539.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    655.99 : 905.34 = 390.56 : x
  2. Step 2: Convert to fraction form
    655.99/905.34 = 390.56/x
  3. Step 3: Cross multiply
    655.99x = 905.34 × 390.56
  4. Step 4: Simplify right side
    655.99x = 353,586.53
  5. Step 5: Solve for x
    x = 353,586.53/655.99
  6. Step 6: Final answer
    x = 539.01

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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.