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Finding the Fourth Proportional to 920.29, 1,270.40 and 640.42

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Solution

The fourth proportional to 920.29, 1,270.40 and 640.42 is: 884.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.29 : 1,270.40 = 640.42 : x
  2. Step 2: Convert to fraction form
    920.29/1,270.40 = 640.42/x
  3. Step 3: Cross multiply
    920.29x = 1,270.40 × 640.42
  4. Step 4: Simplify right side
    920.29x = 813,592.74
  5. Step 5: Solve for x
    x = 813,592.74/920.29
  6. Step 6: Final answer
    x = 884.06

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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.