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Finding the Fourth Proportional to 515.54, 771.51 and 421.91

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Solution

The fourth proportional to 515.54, 771.51 and 421.91 is: 631.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.54 : 771.51 = 421.91 : x
  2. Step 2: Convert to fraction form
    515.54/771.51 = 421.91/x
  3. Step 3: Cross multiply
    515.54x = 771.51 × 421.91
  4. Step 4: Simplify right side
    515.54x = 325,503.93
  5. Step 5: Solve for x
    x = 325,503.93/515.54
  6. Step 6: Final answer
    x = 631.38

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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.