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Finding the Fourth Proportional to 415.05, 621.69 and 386.57

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Solution

The fourth proportional to 415.05, 621.69 and 386.57 is: 579.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    415.05 : 621.69 = 386.57 : x
  2. Step 2: Convert to fraction form
    415.05/621.69 = 386.57/x
  3. Step 3: Cross multiply
    415.05x = 621.69 × 386.57
  4. Step 4: Simplify right side
    415.05x = 240,323.59
  5. Step 5: Solve for x
    x = 240,323.59/415.05
  6. Step 6: Final answer
    x = 579.02

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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.