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Finding the Fourth Proportional to 643.18, 960.43 and 639.34

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Solution

The fourth proportional to 643.18, 960.43 and 639.34 is: 954.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.18 : 960.43 = 639.34 : x
  2. Step 2: Convert to fraction form
    643.18/960.43 = 639.34/x
  3. Step 3: Cross multiply
    643.18x = 960.43 × 639.34
  4. Step 4: Simplify right side
    643.18x = 614,041.32
  5. Step 5: Solve for x
    x = 614,041.32/643.18
  6. Step 6: Final answer
    x = 954.70

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.