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Finding the Fourth Proportional to 279.40, 418.91 and 142.18

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Solution

The fourth proportional to 279.40, 418.91 and 142.18 is: 213.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.40 : 418.91 = 142.18 : x
  2. Step 2: Convert to fraction form
    279.40/418.91 = 142.18/x
  3. Step 3: Cross multiply
    279.40x = 418.91 × 142.18
  4. Step 4: Simplify right side
    279.40x = 59,561.24
  5. Step 5: Solve for x
    x = 59,561.24/279.40
  6. Step 6: Final answer
    x = 213.17

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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.