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Finding the Fourth Proportional to 415.78, 623.73 and 391.06

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Solution

The fourth proportional to 415.78, 623.73 and 391.06 is: 586.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    415.78 : 623.73 = 391.06 : x
  2. Step 2: Convert to fraction form
    415.78/623.73 = 391.06/x
  3. Step 3: Cross multiply
    415.78x = 623.73 × 391.06
  4. Step 4: Simplify right side
    415.78x = 243,915.85
  5. Step 5: Solve for x
    x = 243,915.85/415.78
  6. Step 6: Final answer
    x = 586.65

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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.