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Finding the Fourth Proportional to 830.76, 1,244.46 and 391.40

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Solution

The fourth proportional to 830.76, 1,244.46 and 391.40 is: 586.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.76 : 1,244.46 = 391.40 : x
  2. Step 2: Convert to fraction form
    830.76/1,244.46 = 391.40/x
  3. Step 3: Cross multiply
    830.76x = 1,244.46 × 391.40
  4. Step 4: Simplify right side
    830.76x = 487,081.56
  5. Step 5: Solve for x
    x = 487,081.56/830.76
  6. Step 6: Final answer
    x = 586.31

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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.