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Finding the Fourth Proportional to 720.11, 1,080.18 and 287.26

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Solution

The fourth proportional to 720.11, 1,080.18 and 287.26 is: 430.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.11 : 1,080.18 = 287.26 : x
  2. Step 2: Convert to fraction form
    720.11/1,080.18 = 287.26/x
  3. Step 3: Cross multiply
    720.11x = 1,080.18 × 287.26
  4. Step 4: Simplify right side
    720.11x = 310,289.81
  5. Step 5: Solve for x
    x = 310,289.81/720.11
  6. Step 6: Final answer
    x = 430.89

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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.