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Finding the Fourth Proportional to 978.75, 1,351.49 and 630.05

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Solution

The fourth proportional to 978.75, 1,351.49 and 630.05 is: 869.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    978.75 : 1,351.49 = 630.05 : x
  2. Step 2: Convert to fraction form
    978.75/1,351.49 = 630.05/x
  3. Step 3: Cross multiply
    978.75x = 1,351.49 × 630.05
  4. Step 4: Simplify right side
    978.75x = 851,496.37
  5. Step 5: Solve for x
    x = 851,496.37/978.75
  6. Step 6: Final answer
    x = 869.98

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.