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Finding the Fourth Proportional to 643.63, 964.72 and 421.69

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Solution

The fourth proportional to 643.63, 964.72 and 421.69 is: 632.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.63 : 964.72 = 421.69 : x
  2. Step 2: Convert to fraction form
    643.63/964.72 = 421.69/x
  3. Step 3: Cross multiply
    643.63x = 964.72 × 421.69
  4. Step 4: Simplify right side
    643.63x = 406,812.98
  5. Step 5: Solve for x
    x = 406,812.98/643.63
  6. Step 6: Final answer
    x = 632.06

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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.