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Finding the Fourth Proportional to 978.21, 1,465.25 and 668.61

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Solution

The fourth proportional to 978.21, 1,465.25 and 668.61 is: 1,001.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    978.21 : 1,465.25 = 668.61 : x
  2. Step 2: Convert to fraction form
    978.21/1,465.25 = 668.61/x
  3. Step 3: Cross multiply
    978.21x = 1,465.25 × 668.61
  4. Step 4: Simplify right side
    978.21x = 979,677.46
  5. Step 5: Solve for x
    x = 979,677.46/978.21
  6. Step 6: Final answer
    x = 1,001.50

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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.