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Finding the Fourth Proportional to 666.49, 919.72 and 386.74

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Solution

The fourth proportional to 666.49, 919.72 and 386.74 is: 533.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.49 : 919.72 = 386.74 : x
  2. Step 2: Convert to fraction form
    666.49/919.72 = 386.74/x
  3. Step 3: Cross multiply
    666.49x = 919.72 × 386.74
  4. Step 4: Simplify right side
    666.49x = 355,692.51
  5. Step 5: Solve for x
    x = 355,692.51/666.49
  6. Step 6: Final answer
    x = 533.68

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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.