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Finding the Fourth Proportional to 720.58, 1,080.86 and 309.45

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Solution

The fourth proportional to 720.58, 1,080.86 and 309.45 is: 464.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.58 : 1,080.86 = 309.45 : x
  2. Step 2: Convert to fraction form
    720.58/1,080.86 = 309.45/x
  3. Step 3: Cross multiply
    720.58x = 1,080.86 × 309.45
  4. Step 4: Simplify right side
    720.58x = 334,472.13
  5. Step 5: Solve for x
    x = 334,472.13/720.58
  6. Step 6: Final answer
    x = 464.17

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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.