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Finding the Fourth Proportional to 720.16, 1,080.48 and 257.85

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Solution

The fourth proportional to 720.16, 1,080.48 and 257.85 is: 386.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.16 : 1,080.48 = 257.85 : x
  2. Step 2: Convert to fraction form
    720.16/1,080.48 = 257.85/x
  3. Step 3: Cross multiply
    720.16x = 1,080.48 × 257.85
  4. Step 4: Simplify right side
    720.16x = 278,601.77
  5. Step 5: Solve for x
    x = 278,601.77/720.16
  6. Step 6: Final answer
    x = 386.86

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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.