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Finding the Fourth Proportional to 678.48, 1,012.80 and 627.75

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Solution

The fourth proportional to 678.48, 1,012.80 and 627.75 is: 937.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.48 : 1,012.80 = 627.75 : x
  2. Step 2: Convert to fraction form
    678.48/1,012.80 = 627.75/x
  3. Step 3: Cross multiply
    678.48x = 1,012.80 × 627.75
  4. Step 4: Simplify right side
    678.48x = 635,787.55
  5. Step 5: Solve for x
    x = 635,787.55/678.48
  6. Step 6: Final answer
    x = 937.08

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.