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Finding the Fourth Proportional to 720.85, 1,080.95 and 355.49

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Solution

The fourth proportional to 720.85, 1,080.95 and 355.49 is: 533.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.85 : 1,080.95 = 355.49 : x
  2. Step 2: Convert to fraction form
    720.85/1,080.95 = 355.49/x
  3. Step 3: Cross multiply
    720.85x = 1,080.95 × 355.49
  4. Step 4: Simplify right side
    720.85x = 384,263.79
  5. Step 5: Solve for x
    x = 384,263.79/720.85
  6. Step 6: Final answer
    x = 533.07

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.