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Finding the Fourth Proportional to 739.28, 1,109.28 and 430.40

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Solution

The fourth proportional to 739.28, 1,109.28 and 430.40 is: 645.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    739.28 : 1,109.28 = 430.40 : x
  2. Step 2: Convert to fraction form
    739.28/1,109.28 = 430.40/x
  3. Step 3: Cross multiply
    739.28x = 1,109.28 × 430.40
  4. Step 4: Simplify right side
    739.28x = 477,434.11
  5. Step 5: Solve for x
    x = 477,434.11/739.28
  6. Step 6: Final answer
    x = 645.81

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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.