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Finding the Fourth Proportional to 642.16, 885.68 and 495.20

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Solution

The fourth proportional to 642.16, 885.68 and 495.20 is: 682.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.16 : 885.68 = 495.20 : x
  2. Step 2: Convert to fraction form
    642.16/885.68 = 495.20/x
  3. Step 3: Cross multiply
    642.16x = 885.68 × 495.20
  4. Step 4: Simplify right side
    642.16x = 438,588.74
  5. Step 5: Solve for x
    x = 438,588.74/642.16
  6. Step 6: Final answer
    x = 682.99

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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.