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Finding the Fourth Proportional to 429.80, 641.00 and 388.28

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Solution

The fourth proportional to 429.80, 641.00 and 388.28 is: 579.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.80 : 641.00 = 388.28 : x
  2. Step 2: Convert to fraction form
    429.80/641.00 = 388.28/x
  3. Step 3: Cross multiply
    429.80x = 641.00 × 388.28
  4. Step 4: Simplify right side
    429.80x = 248,884.26
  5. Step 5: Solve for x
    x = 248,884.26/429.80
  6. Step 6: Final answer
    x = 579.07

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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.