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Finding the Fourth Proportional to 427.20, 641.68 and 290.48

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Solution

The fourth proportional to 427.20, 641.68 and 290.48 is: 436.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.20 : 641.68 = 290.48 : x
  2. Step 2: Convert to fraction form
    427.20/641.68 = 290.48/x
  3. Step 3: Cross multiply
    427.20x = 641.68 × 290.48
  4. Step 4: Simplify right side
    427.20x = 186,395.21
  5. Step 5: Solve for x
    x = 186,395.21/427.20
  6. Step 6: Final answer
    x = 436.32

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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.