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Finding the Fourth Proportional to 642.08, 885.84 and 409.60

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Solution

The fourth proportional to 642.08, 885.84 and 409.60 is: 565.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.08 : 885.84 = 409.60 : x
  2. Step 2: Convert to fraction form
    642.08/885.84 = 409.60/x
  3. Step 3: Cross multiply
    642.08x = 885.84 × 409.60
  4. Step 4: Simplify right side
    642.08x = 362,840.06
  5. Step 5: Solve for x
    x = 362,840.06/642.08
  6. Step 6: Final answer
    x = 565.10

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.