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Finding the Fourth Proportional to 430.24, 645.04 and 386.78

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Solution

The fourth proportional to 430.24, 645.04 and 386.78 is: 579.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.24 : 645.04 = 386.78 : x
  2. Step 2: Convert to fraction form
    430.24/645.04 = 386.78/x
  3. Step 3: Cross multiply
    430.24x = 645.04 × 386.78
  4. Step 4: Simplify right side
    430.24x = 249,488.57
  5. Step 5: Solve for x
    x = 249,488.57/430.24
  6. Step 6: Final answer
    x = 579.88

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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.