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Finding the Fourth Proportional to 478.77, 722.13 and 421.71

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Solution

The fourth proportional to 478.77, 722.13 and 421.71 is: 636.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.77 : 722.13 = 421.71 : x
  2. Step 2: Convert to fraction form
    478.77/722.13 = 421.71/x
  3. Step 3: Cross multiply
    478.77x = 722.13 × 421.71
  4. Step 4: Simplify right side
    478.77x = 304,527.53
  5. Step 5: Solve for x
    x = 304,527.53/478.77
  6. Step 6: Final answer
    x = 636.06

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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.