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Finding the Fourth Proportional to 651.68, 978.20 and 378.31

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Solution

The fourth proportional to 651.68, 978.20 and 378.31 is: 567.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    651.68 : 978.20 = 378.31 : x
  2. Step 2: Convert to fraction form
    651.68/978.20 = 378.31/x
  3. Step 3: Cross multiply
    651.68x = 978.20 × 378.31
  4. Step 4: Simplify right side
    651.68x = 370,062.84
  5. Step 5: Solve for x
    x = 370,062.84/651.68
  6. Step 6: Final answer
    x = 567.86

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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.