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Finding the Fourth Proportional to 720.40, 1,080.06 and 309.10

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Solution

The fourth proportional to 720.40, 1,080.06 and 309.10 is: 463.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.40 : 1,080.06 = 309.10 : x
  2. Step 2: Convert to fraction form
    720.40/1,080.06 = 309.10/x
  3. Step 3: Cross multiply
    720.40x = 1,080.06 × 309.10
  4. Step 4: Simplify right side
    720.40x = 333,846.55
  5. Step 5: Solve for x
    x = 333,846.55/720.40
  6. Step 6: Final answer
    x = 463.42

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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.