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Finding the Fourth Proportional to 415.78, 621.49 and 407.14

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Solution

The fourth proportional to 415.78, 621.49 and 407.14 is: 608.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    415.78 : 621.49 = 407.14 : x
  2. Step 2: Convert to fraction form
    415.78/621.49 = 407.14/x
  3. Step 3: Cross multiply
    415.78x = 621.49 × 407.14
  4. Step 4: Simplify right side
    415.78x = 253,033.44
  5. Step 5: Solve for x
    x = 253,033.44/415.78
  6. Step 6: Final answer
    x = 608.58

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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.