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Finding the Fourth Proportional to 421.39, 631.14 and 411.07

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Solution

The fourth proportional to 421.39, 631.14 and 411.07 is: 615.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.39 : 631.14 = 411.07 : x
  2. Step 2: Convert to fraction form
    421.39/631.14 = 411.07/x
  3. Step 3: Cross multiply
    421.39x = 631.14 × 411.07
  4. Step 4: Simplify right side
    421.39x = 259,442.72
  5. Step 5: Solve for x
    x = 259,442.72/421.39
  6. Step 6: Final answer
    x = 615.68

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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.