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Finding the Fourth Proportional to 279.30, 419 and 86.88

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Solution

The fourth proportional to 279.30, 419 and 86.88 is: 130.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.30 : 419 = 86.88 : x
  2. Step 2: Convert to fraction form
    279.30/419 = 86.88/x
  3. Step 3: Cross multiply
    279.30x = 419 × 86.88
  4. Step 4: Simplify right side
    279.30x = 36,402.72
  5. Step 5: Solve for x
    x = 36,402.72/279.30
  6. Step 6: Final answer
    x = 130.34

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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.