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Finding the Fourth Proportional to 640.40, 884.20 and 404.40

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Solution

The fourth proportional to 640.40, 884.20 and 404.40 is: 558.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.40 : 884.20 = 404.40 : x
  2. Step 2: Convert to fraction form
    640.40/884.20 = 404.40/x
  3. Step 3: Cross multiply
    640.40x = 884.20 × 404.40
  4. Step 4: Simplify right side
    640.40x = 357,570.48
  5. Step 5: Solve for x
    x = 357,570.48/640.40
  6. Step 6: Final answer
    x = 558.35

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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.