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Finding the Fourth Proportional to 430.90, 646.44 and 199.78

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Solution

The fourth proportional to 430.90, 646.44 and 199.78 is: 299.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.90 : 646.44 = 199.78 : x
  2. Step 2: Convert to fraction form
    430.90/646.44 = 199.78/x
  3. Step 3: Cross multiply
    430.90x = 646.44 × 199.78
  4. Step 4: Simplify right side
    430.90x = 129,145.78
  5. Step 5: Solve for x
    x = 129,145.78/430.90
  6. Step 6: Final answer
    x = 299.71

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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.