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Finding the Fourth Proportional to 430.95, 646.41 and 138.47

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Solution

The fourth proportional to 430.95, 646.41 and 138.47 is: 207.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.95 : 646.41 = 138.47 : x
  2. Step 2: Convert to fraction form
    430.95/646.41 = 138.47/x
  3. Step 3: Cross multiply
    430.95x = 646.41 × 138.47
  4. Step 4: Simplify right side
    430.95x = 89,505.68
  5. Step 5: Solve for x
    x = 89,505.68/430.95
  6. Step 6: Final answer
    x = 207.69

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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.