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Finding the Fourth Proportional to 669.39, 923.61 and 420.76

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Solution

The fourth proportional to 669.39, 923.61 and 420.76 is: 580.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.39 : 923.61 = 420.76 : x
  2. Step 2: Convert to fraction form
    669.39/923.61 = 420.76/x
  3. Step 3: Cross multiply
    669.39x = 923.61 × 420.76
  4. Step 4: Simplify right side
    669.39x = 388,618.14
  5. Step 5: Solve for x
    x = 388,618.14/669.39
  6. Step 6: Final answer
    x = 580.56

Related Problems

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Half scale
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Double scale
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1.5x scale

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.