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Finding the Fourth Proportional to 659.50, 989.30 and 172.55

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Solution

The fourth proportional to 659.50, 989.30 and 172.55 is: 258.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.50 : 989.30 = 172.55 : x
  2. Step 2: Convert to fraction form
    659.50/989.30 = 172.55/x
  3. Step 3: Cross multiply
    659.50x = 989.30 × 172.55
  4. Step 4: Simplify right side
    659.50x = 170,700.81
  5. Step 5: Solve for x
    x = 170,700.81/659.50
  6. Step 6: Final answer
    x = 258.84

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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.