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Finding the Fourth Proportional to 643.19, 964.78 and 156.25

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Solution

The fourth proportional to 643.19, 964.78 and 156.25 is: 234.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.19 : 964.78 = 156.25 : x
  2. Step 2: Convert to fraction form
    643.19/964.78 = 156.25/x
  3. Step 3: Cross multiply
    643.19x = 964.78 × 156.25
  4. Step 4: Simplify right side
    643.19x = 150,744.07
  5. Step 5: Solve for x
    x = 150,744.07/643.19
  6. Step 6: Final answer
    x = 234.37

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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.