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Finding the Fourth Proportional to 712.80, 1,069.26 and 280.26

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Solution

The fourth proportional to 712.80, 1,069.26 and 280.26 is: 420.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    712.80 : 1,069.26 = 280.26 : x
  2. Step 2: Convert to fraction form
    712.80/1,069.26 = 280.26/x
  3. Step 3: Cross multiply
    712.80x = 1,069.26 × 280.26
  4. Step 4: Simplify right side
    712.80x = 299,670.81
  5. Step 5: Solve for x
    x = 299,670.81/712.80
  6. Step 6: Final answer
    x = 420.41

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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.