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Finding the Fourth Proportional to 648.78, 972.49 and 278.81

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Solution

The fourth proportional to 648.78, 972.49 and 278.81 is: 417.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.78 : 972.49 = 278.81 : x
  2. Step 2: Convert to fraction form
    648.78/972.49 = 278.81/x
  3. Step 3: Cross multiply
    648.78x = 972.49 × 278.81
  4. Step 4: Simplify right side
    648.78x = 271,139.94
  5. Step 5: Solve for x
    x = 271,139.94/648.78
  6. Step 6: Final answer
    x = 417.92

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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.