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Finding the Fourth Proportional to 659.64, 989.44 and 221

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Solution

The fourth proportional to 659.64, 989.44 and 221 is: 331.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.64 : 989.44 = 221 : x
  2. Step 2: Convert to fraction form
    659.64/989.44 = 221/x
  3. Step 3: Cross multiply
    659.64x = 989.44 × 221
  4. Step 4: Simplify right side
    659.64x = 218,666.24
  5. Step 5: Solve for x
    x = 218,666.24/659.64
  6. Step 6: Final answer
    x = 331.49

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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.