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Finding the Fourth Proportional to 430.71, 646.02 and 138.21

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Solution

The fourth proportional to 430.71, 646.02 and 138.21 is: 207.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.71 : 646.02 = 138.21 : x
  2. Step 2: Convert to fraction form
    430.71/646.02 = 138.21/x
  3. Step 3: Cross multiply
    430.71x = 646.02 × 138.21
  4. Step 4: Simplify right side
    430.71x = 89,286.42
  5. Step 5: Solve for x
    x = 89,286.42/430.71
  6. Step 6: Final answer
    x = 207.30

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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.