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Finding the Fourth Proportional to 720.72, 1,080.72 and 288

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Solution

The fourth proportional to 720.72, 1,080.72 and 288 is: 431.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.72 : 1,080.72 = 288 : x
  2. Step 2: Convert to fraction form
    720.72/1,080.72 = 288/x
  3. Step 3: Cross multiply
    720.72x = 1,080.72 × 288
  4. Step 4: Simplify right side
    720.72x = 311,247.36
  5. Step 5: Solve for x
    x = 311,247.36/720.72
  6. Step 6: Final answer
    x = 431.86

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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.