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Finding the Fourth Proportional to 430.28, 641.83 and 388.75

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Solution

The fourth proportional to 430.28, 641.83 and 388.75 is: 579.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    430.28 : 641.83 = 388.75 : x
  2. Step 2: Convert to fraction form
    430.28/641.83 = 388.75/x
  3. Step 3: Cross multiply
    430.28x = 641.83 × 388.75
  4. Step 4: Simplify right side
    430.28x = 249,513.90
  5. Step 5: Solve for x
    x = 249,513.90/430.28
  6. Step 6: Final answer
    x = 579.89

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.