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Finding the Fourth Proportional to 280.27, 420.71 and 143.28

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Solution

The fourth proportional to 280.27, 420.71 and 143.28 is: 215.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.27 : 420.71 = 143.28 : x
  2. Step 2: Convert to fraction form
    280.27/420.71 = 143.28/x
  3. Step 3: Cross multiply
    280.27x = 420.71 × 143.28
  4. Step 4: Simplify right side
    280.27x = 60,279.33
  5. Step 5: Solve for x
    x = 60,279.33/280.27
  6. Step 6: Final answer
    x = 215.08

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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.