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Finding the Fourth Proportional to 659.90, 989.85 and 172.89

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Solution

The fourth proportional to 659.90, 989.85 and 172.89 is: 259.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.90 : 989.85 = 172.89 : x
  2. Step 2: Convert to fraction form
    659.90/989.85 = 172.89/x
  3. Step 3: Cross multiply
    659.90x = 989.85 × 172.89
  4. Step 4: Simplify right side
    659.90x = 171,135.17
  5. Step 5: Solve for x
    x = 171,135.17/659.90
  6. Step 6: Final answer
    x = 259.34

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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.