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Finding the Fourth Proportional to 279.85, 420.68 and 172.32

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Solution

The fourth proportional to 279.85, 420.68 and 172.32 is: 259.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.85 : 420.68 = 172.32 : x
  2. Step 2: Convert to fraction form
    279.85/420.68 = 172.32/x
  3. Step 3: Cross multiply
    279.85x = 420.68 × 172.32
  4. Step 4: Simplify right side
    279.85x = 72,488.61
  5. Step 5: Solve for x
    x = 72,488.61/279.85
  6. Step 6: Final answer
    x = 259.03

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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.