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Finding the Fourth Proportional to 720.04, 1,080.12 and 257.80

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Solution

The fourth proportional to 720.04, 1,080.12 and 257.80 is: 386.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.04 : 1,080.12 = 257.80 : x
  2. Step 2: Convert to fraction form
    720.04/1,080.12 = 257.80/x
  3. Step 3: Cross multiply
    720.04x = 1,080.12 × 257.80
  4. Step 4: Simplify right side
    720.04x = 278,448.25
  5. Step 5: Solve for x
    x = 278,448.25/720.04
  6. Step 6: Final answer
    x = 386.71

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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.