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Finding the Fourth Proportional to 669.40, 1,004.10 and 345.40

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Solution

The fourth proportional to 669.40, 1,004.10 and 345.40 is: 518.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.40 : 1,004.10 = 345.40 : x
  2. Step 2: Convert to fraction form
    669.40/1,004.10 = 345.40/x
  3. Step 3: Cross multiply
    669.40x = 1,004.10 × 345.40
  4. Step 4: Simplify right side
    669.40x = 346,816.14
  5. Step 5: Solve for x
    x = 346,816.14/669.40
  6. Step 6: Final answer
    x = 518.10

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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.