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Finding the Fourth Proportional to 720.30, 1,080.42 and 258.09

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Solution

The fourth proportional to 720.30, 1,080.42 and 258.09 is: 387.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.30 : 1,080.42 = 258.09 : x
  2. Step 2: Convert to fraction form
    720.30/1,080.42 = 258.09/x
  3. Step 3: Cross multiply
    720.30x = 1,080.42 × 258.09
  4. Step 4: Simplify right side
    720.30x = 278,845.60
  5. Step 5: Solve for x
    x = 278,845.60/720.30
  6. Step 6: Final answer
    x = 387.12

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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.