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Finding the Fourth Proportional to 659.40, 989.09 and 172.45

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Solution

The fourth proportional to 659.40, 989.09 and 172.45 is: 258.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.40 : 989.09 = 172.45 : x
  2. Step 2: Convert to fraction form
    659.40/989.09 = 172.45/x
  3. Step 3: Cross multiply
    659.40x = 989.09 × 172.45
  4. Step 4: Simplify right side
    659.40x = 170,568.57
  5. Step 5: Solve for x
    x = 170,568.57/659.40
  6. Step 6: Final answer
    x = 258.67

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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.