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Finding the Fourth Proportional to 717.28, 989.84 and 406.80

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Solution

The fourth proportional to 717.28, 989.84 and 406.80 is: 561.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.28 : 989.84 = 406.80 : x
  2. Step 2: Convert to fraction form
    717.28/989.84 = 406.80/x
  3. Step 3: Cross multiply
    717.28x = 989.84 × 406.80
  4. Step 4: Simplify right side
    717.28x = 402,666.91
  5. Step 5: Solve for x
    x = 402,666.91/717.28
  6. Step 6: Final answer
    x = 561.38

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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.