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Finding the Fourth Proportional to 279.40, 419.18 and 84.42

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Solution

The fourth proportional to 279.40, 419.18 and 84.42 is: 126.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.40 : 419.18 = 84.42 : x
  2. Step 2: Convert to fraction form
    279.40/419.18 = 84.42/x
  3. Step 3: Cross multiply
    279.40x = 419.18 × 84.42
  4. Step 4: Simplify right side
    279.40x = 35,385.57
  5. Step 5: Solve for x
    x = 35,385.57/279.40
  6. Step 6: Final answer
    x = 126.65

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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.