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Finding the Fourth Proportional to 659.19, 988.66 and 172.21

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Solution

The fourth proportional to 659.19, 988.66 and 172.21 is: 258.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.19 : 988.66 = 172.21 : x
  2. Step 2: Convert to fraction form
    659.19/988.66 = 172.21/x
  3. Step 3: Cross multiply
    659.19x = 988.66 × 172.21
  4. Step 4: Simplify right side
    659.19x = 170,251.33
  5. Step 5: Solve for x
    x = 170,251.33/659.19
  6. Step 6: Final answer
    x = 258.28

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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.