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Finding the Fourth Proportional to 830.78, 1,246.38 and 310.80

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Solution

The fourth proportional to 830.78, 1,246.38 and 310.80 is: 466.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.78 : 1,246.38 = 310.80 : x
  2. Step 2: Convert to fraction form
    830.78/1,246.38 = 310.80/x
  3. Step 3: Cross multiply
    830.78x = 1,246.38 × 310.80
  4. Step 4: Simplify right side
    830.78x = 387,374.90
  5. Step 5: Solve for x
    x = 387,374.90/830.78
  6. Step 6: Final answer
    x = 466.28

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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.