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Finding the Fourth Proportional to 678.35, 1,019.70 and 630.20

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Solution

The fourth proportional to 678.35, 1,019.70 and 630.20 is: 947.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.35 : 1,019.70 = 630.20 : x
  2. Step 2: Convert to fraction form
    678.35/1,019.70 = 630.20/x
  3. Step 3: Cross multiply
    678.35x = 1,019.70 × 630.20
  4. Step 4: Simplify right side
    678.35x = 642,614.94
  5. Step 5: Solve for x
    x = 642,614.94/678.35
  6. Step 6: Final answer
    x = 947.32

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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.