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Finding the Fourth Proportional to 1,013.32, 1,398.09 and 640.78

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Solution

The fourth proportional to 1,013.32, 1,398.09 and 640.78 is: 884.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,013.32 : 1,398.09 = 640.78 : x
  2. Step 2: Convert to fraction form
    1,013.32/1,398.09 = 640.78/x
  3. Step 3: Cross multiply
    1,013.32x = 1,398.09 × 640.78
  4. Step 4: Simplify right side
    1,013.32x = 895,867.02
  5. Step 5: Solve for x
    x = 895,867.02/1,013.32
  6. Step 6: Final answer
    x = 884.09

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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.