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Finding the Fourth Proportional to 666.68, 919.80 and 400.95

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Solution

The fourth proportional to 666.68, 919.80 and 400.95 is: 553.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.68 : 919.80 = 400.95 : x
  2. Step 2: Convert to fraction form
    666.68/919.80 = 400.95/x
  3. Step 3: Cross multiply
    666.68x = 919.80 × 400.95
  4. Step 4: Simplify right side
    666.68x = 368,793.81
  5. Step 5: Solve for x
    x = 368,793.81/666.68
  6. Step 6: Final answer
    x = 553.18

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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.