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Finding the Fourth Proportional to 669.60, 1,003.80 and 438.60

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Solution

The fourth proportional to 669.60, 1,003.80 and 438.60 is: 657.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.60 : 1,003.80 = 438.60 : x
  2. Step 2: Convert to fraction form
    669.60/1,003.80 = 438.60/x
  3. Step 3: Cross multiply
    669.60x = 1,003.80 × 438.60
  4. Step 4: Simplify right side
    669.60x = 440,266.68
  5. Step 5: Solve for x
    x = 440,266.68/669.60
  6. Step 6: Final answer
    x = 657.51

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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.