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Finding the Fourth Proportional to 430.96, 646.49 and 138.38

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Solution

The fourth proportional to 430.96, 646.49 and 138.38 is: 207.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.96 : 646.49 = 138.38 : x
  2. Step 2: Convert to fraction form
    430.96/646.49 = 138.38/x
  3. Step 3: Cross multiply
    430.96x = 646.49 × 138.38
  4. Step 4: Simplify right side
    430.96x = 89,457.36
  5. Step 5: Solve for x
    x = 89,457.36/430.96
  6. Step 6: Final answer
    x = 207.58

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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.