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Finding the Fourth Proportional to 628.99, 868.09 and 393.18

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Solution

The fourth proportional to 628.99, 868.09 and 393.18 is: 542.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.99 : 868.09 = 393.18 : x
  2. Step 2: Convert to fraction form
    628.99/868.09 = 393.18/x
  3. Step 3: Cross multiply
    628.99x = 868.09 × 393.18
  4. Step 4: Simplify right side
    628.99x = 341,315.63
  5. Step 5: Solve for x
    x = 341,315.63/628.99
  6. Step 6: Final answer
    x = 542.64

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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.