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Finding the Fourth Proportional to 978.67, 1,350.94 and 647.55

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Solution

The fourth proportional to 978.67, 1,350.94 and 647.55 is: 893.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    978.67 : 1,350.94 = 647.55 : x
  2. Step 2: Convert to fraction form
    978.67/1,350.94 = 647.55/x
  3. Step 3: Cross multiply
    978.67x = 1,350.94 × 647.55
  4. Step 4: Simplify right side
    978.67x = 874,801.20
  5. Step 5: Solve for x
    x = 874,801.20/978.67
  6. Step 6: Final answer
    x = 893.87

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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.