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Finding the Fourth Proportional to 638.11, 957.16 and 421.63

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Solution

The fourth proportional to 638.11, 957.16 and 421.63 is: 632.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.11 : 957.16 = 421.63 : x
  2. Step 2: Convert to fraction form
    638.11/957.16 = 421.63/x
  3. Step 3: Cross multiply
    638.11x = 957.16 × 421.63
  4. Step 4: Simplify right side
    638.11x = 403,568.71
  5. Step 5: Solve for x
    x = 403,568.71/638.11
  6. Step 6: Final answer
    x = 632.45

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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.