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Finding the Fourth Proportional to 720.80, 1,080.29 and 309.46

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Solution

The fourth proportional to 720.80, 1,080.29 and 309.46 is: 463.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.80 : 1,080.29 = 309.46 : x
  2. Step 2: Convert to fraction form
    720.80/1,080.29 = 309.46/x
  3. Step 3: Cross multiply
    720.80x = 1,080.29 × 309.46
  4. Step 4: Simplify right side
    720.80x = 334,301.14
  5. Step 5: Solve for x
    x = 334,301.14/720.80
  6. Step 6: Final answer
    x = 463.79

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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.