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Finding the Fourth Proportional to 438, 657.22 and 412.78

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Solution

The fourth proportional to 438, 657.22 and 412.78 is: 619.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    438 : 657.22 = 412.78 : x
  2. Step 2: Convert to fraction form
    438/657.22 = 412.78/x
  3. Step 3: Cross multiply
    438x = 657.22 × 412.78
  4. Step 4: Simplify right side
    438x = 271,287.27
  5. Step 5: Solve for x
    x = 271,287.27/438
  6. Step 6: Final answer
    x = 619.38

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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.