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Finding the Fourth Proportional to 430.86, 645.65 and 199.20

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Solution

The fourth proportional to 430.86, 645.65 and 199.20 is: 298.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.86 : 645.65 = 199.20 : x
  2. Step 2: Convert to fraction form
    430.86/645.65 = 199.20/x
  3. Step 3: Cross multiply
    430.86x = 645.65 × 199.20
  4. Step 4: Simplify right side
    430.86x = 128,613.48
  5. Step 5: Solve for x
    x = 128,613.48/430.86
  6. Step 6: Final answer
    x = 298.50

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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.