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Finding the Fourth Proportional to 279.86, 420.26 and 243.68

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Solution

The fourth proportional to 279.86, 420.26 and 243.68 is: 365.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.86 : 420.26 = 243.68 : x
  2. Step 2: Convert to fraction form
    279.86/420.26 = 243.68/x
  3. Step 3: Cross multiply
    279.86x = 420.26 × 243.68
  4. Step 4: Simplify right side
    279.86x = 102,405.64
  5. Step 5: Solve for x
    x = 102,405.64/279.86
  6. Step 6: Final answer
    x = 365.92

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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.