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Finding the Fourth Proportional to 278.72, 420.24 and 260.16

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Solution

The fourth proportional to 278.72, 420.24 and 260.16 is: 392.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.72 : 420.24 = 260.16 : x
  2. Step 2: Convert to fraction form
    278.72/420.24 = 260.16/x
  3. Step 3: Cross multiply
    278.72x = 420.24 × 260.16
  4. Step 4: Simplify right side
    278.72x = 109,329.64
  5. Step 5: Solve for x
    x = 109,329.64/278.72
  6. Step 6: Final answer
    x = 392.26

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.