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Finding the Fourth Proportional to 643.40, 966.30 and 400.40

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Solution

The fourth proportional to 643.40, 966.30 and 400.40 is: 601.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.40 : 966.30 = 400.40 : x
  2. Step 2: Convert to fraction form
    643.40/966.30 = 400.40/x
  3. Step 3: Cross multiply
    643.40x = 966.30 × 400.40
  4. Step 4: Simplify right side
    643.40x = 386,906.52
  5. Step 5: Solve for x
    x = 386,906.52/643.40
  6. Step 6: Final answer
    x = 601.35

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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.