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Finding the Fourth Proportional to 666.81, 920.19 and 404.64

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Solution

The fourth proportional to 666.81, 920.19 and 404.64 is: 558.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.81 : 920.19 = 404.64 : x
  2. Step 2: Convert to fraction form
    666.81/920.19 = 404.64/x
  3. Step 3: Cross multiply
    666.81x = 920.19 × 404.64
  4. Step 4: Simplify right side
    666.81x = 372,345.68
  5. Step 5: Solve for x
    x = 372,345.68/666.81
  6. Step 6: Final answer
    x = 558.40

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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.