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Finding the Fourth Proportional to 720.28, 993.99 and 409.78

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Solution

The fourth proportional to 720.28, 993.99 and 409.78 is: 565.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.28 : 993.99 = 409.78 : x
  2. Step 2: Convert to fraction form
    720.28/993.99 = 409.78/x
  3. Step 3: Cross multiply
    720.28x = 993.99 × 409.78
  4. Step 4: Simplify right side
    720.28x = 407,317.22
  5. Step 5: Solve for x
    x = 407,317.22/720.28
  6. Step 6: Final answer
    x = 565.50

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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.