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Finding the Fourth Proportional to 668.76, 922.72 and 420.20

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Solution

The fourth proportional to 668.76, 922.72 and 420.20 is: 579.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.76 : 922.72 = 420.20 : x
  2. Step 2: Convert to fraction form
    668.76/922.72 = 420.20/x
  3. Step 3: Cross multiply
    668.76x = 922.72 × 420.20
  4. Step 4: Simplify right side
    668.76x = 387,726.94
  5. Step 5: Solve for x
    x = 387,726.94/668.76
  6. Step 6: Final answer
    x = 579.77

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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.