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Finding the Fourth Proportional to 421.88, 634.01 and 278.51

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Solution

The fourth proportional to 421.88, 634.01 and 278.51 is: 418.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.88 : 634.01 = 278.51 : x
  2. Step 2: Convert to fraction form
    421.88/634.01 = 278.51/x
  3. Step 3: Cross multiply
    421.88x = 634.01 × 278.51
  4. Step 4: Simplify right side
    421.88x = 176,573.56
  5. Step 5: Solve for x
    x = 176,573.56/421.88
  6. Step 6: Final answer
    x = 418.54

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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.