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Finding the Fourth Proportional to 561, 840.40 and 286.28

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Solution

The fourth proportional to 561, 840.40 and 286.28 is: 428.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    561 : 840.40 = 286.28 : x
  2. Step 2: Convert to fraction form
    561/840.40 = 286.28/x
  3. Step 3: Cross multiply
    561x = 840.40 × 286.28
  4. Step 4: Simplify right side
    561x = 240,589.71
  5. Step 5: Solve for x
    x = 240,589.71/561
  6. Step 6: Final answer
    x = 428.86

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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.