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Finding the Fourth Proportional to 278.57, 415.38 and 259.72

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Solution

The fourth proportional to 278.57, 415.38 and 259.72 is: 387.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.57 : 415.38 = 259.72 : x
  2. Step 2: Convert to fraction form
    278.57/415.38 = 259.72/x
  3. Step 3: Cross multiply
    278.57x = 415.38 × 259.72
  4. Step 4: Simplify right side
    278.57x = 107,881.46
  5. Step 5: Solve for x
    x = 107,881.46/278.57
  6. Step 6: Final answer
    x = 387.28

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.