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Finding the Fourth Proportional to 280.84, 421.40 and 165.20

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Solution

The fourth proportional to 280.84, 421.40 and 165.20 is: 247.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.84 : 421.40 = 165.20 : x
  2. Step 2: Convert to fraction form
    280.84/421.40 = 165.20/x
  3. Step 3: Cross multiply
    280.84x = 421.40 × 165.20
  4. Step 4: Simplify right side
    280.84x = 69,615.28
  5. Step 5: Solve for x
    x = 69,615.28/280.84
  6. Step 6: Final answer
    x = 247.88

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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.