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Finding the Fourth Proportional to 720, 1,079.88 and 309.36

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Solution

The fourth proportional to 720, 1,079.88 and 309.36 is: 463.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    720 : 1,079.88 = 309.36 : x
  2. Step 2: Convert to fraction form
    720/1,079.88 = 309.36/x
  3. Step 3: Cross multiply
    720x = 1,079.88 × 309.36
  4. Step 4: Simplify right side
    720x = 334,071.68
  5. Step 5: Solve for x
    x = 334,071.68/720
  6. Step 6: Final answer
    x = 463.99

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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.