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Finding the Fourth Proportional to 430.12, 645.18 and 386.92

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Solution

The fourth proportional to 430.12, 645.18 and 386.92 is: 580.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.12 : 645.18 = 386.92 : x
  2. Step 2: Convert to fraction form
    430.12/645.18 = 386.92/x
  3. Step 3: Cross multiply
    430.12x = 645.18 × 386.92
  4. Step 4: Simplify right side
    430.12x = 249,633.05
  5. Step 5: Solve for x
    x = 249,633.05/430.12
  6. Step 6: Final answer
    x = 580.38

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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.