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Finding the Fourth Proportional to 430.69, 645.78 and 199.66

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Solution

The fourth proportional to 430.69, 645.78 and 199.66 is: 299.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.69 : 645.78 = 199.66 : x
  2. Step 2: Convert to fraction form
    430.69/645.78 = 199.66/x
  3. Step 3: Cross multiply
    430.69x = 645.78 × 199.66
  4. Step 4: Simplify right side
    430.69x = 128,936.43
  5. Step 5: Solve for x
    x = 128,936.43/430.69
  6. Step 6: Final answer
    x = 299.37

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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.