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Finding the Fourth Proportional to 418.08, 630.36 and 390.24

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Solution

The fourth proportional to 418.08, 630.36 and 390.24 is: 588.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.08 : 630.36 = 390.24 : x
  2. Step 2: Convert to fraction form
    418.08/630.36 = 390.24/x
  3. Step 3: Cross multiply
    418.08x = 630.36 × 390.24
  4. Step 4: Simplify right side
    418.08x = 245,991.69
  5. Step 5: Solve for x
    x = 245,991.69/418.08
  6. Step 6: Final answer
    x = 588.38

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.