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Finding the Fourth Proportional to 611.78, 916.07 and 405.69

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Solution

The fourth proportional to 611.78, 916.07 and 405.69 is: 607.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.78 : 916.07 = 405.69 : x
  2. Step 2: Convert to fraction form
    611.78/916.07 = 405.69/x
  3. Step 3: Cross multiply
    611.78x = 916.07 × 405.69
  4. Step 4: Simplify right side
    611.78x = 371,638.41
  5. Step 5: Solve for x
    x = 371,638.41/611.78
  6. Step 6: Final answer
    x = 607.48

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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.