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Finding the Fourth Proportional to 669.40, 923.47 and 420.59

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Solution

The fourth proportional to 669.40, 923.47 and 420.59 is: 580.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.40 : 923.47 = 420.59 : x
  2. Step 2: Convert to fraction form
    669.40/923.47 = 420.59/x
  3. Step 3: Cross multiply
    669.40x = 923.47 × 420.59
  4. Step 4: Simplify right side
    669.40x = 388,403.50
  5. Step 5: Solve for x
    x = 388,403.50/669.40
  6. Step 6: Final answer
    x = 580.23

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.