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Finding the Fourth Proportional to 279.75, 419.70 and 87.39

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Solution

The fourth proportional to 279.75, 419.70 and 87.39 is: 131.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.75 : 419.70 = 87.39 : x
  2. Step 2: Convert to fraction form
    279.75/419.70 = 87.39/x
  3. Step 3: Cross multiply
    279.75x = 419.70 × 87.39
  4. Step 4: Simplify right side
    279.75x = 36,677.58
  5. Step 5: Solve for x
    x = 36,677.58/279.75
  6. Step 6: Final answer
    x = 131.11

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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.