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Finding the Fourth Proportional to 938.49, 1,406.98 and 391.09

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Solution

The fourth proportional to 938.49, 1,406.98 and 391.09 is: 586.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    938.49 : 1,406.98 = 391.09 : x
  2. Step 2: Convert to fraction form
    938.49/1,406.98 = 391.09/x
  3. Step 3: Cross multiply
    938.49x = 1,406.98 × 391.09
  4. Step 4: Simplify right side
    938.49x = 550,246.82
  5. Step 5: Solve for x
    x = 550,246.82/938.49
  6. Step 6: Final answer
    x = 586.31

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.