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Finding the Fourth Proportional to 643.09, 887.80 and 495.40

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Solution

The fourth proportional to 643.09, 887.80 and 495.40 is: 683.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.09 : 887.80 = 495.40 : x
  2. Step 2: Convert to fraction form
    643.09/887.80 = 495.40/x
  3. Step 3: Cross multiply
    643.09x = 887.80 × 495.40
  4. Step 4: Simplify right side
    643.09x = 439,816.12
  5. Step 5: Solve for x
    x = 439,816.12/643.09
  6. Step 6: Final answer
    x = 683.91

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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.