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Finding the Fourth Proportional to 688.80, 1,032.60 and 615.90

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Solution

The fourth proportional to 688.80, 1,032.60 and 615.90 is: 923.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.80 : 1,032.60 = 615.90 : x
  2. Step 2: Convert to fraction form
    688.80/1,032.60 = 615.90/x
  3. Step 3: Cross multiply
    688.80x = 1,032.60 × 615.90
  4. Step 4: Simplify right side
    688.80x = 635,978.34
  5. Step 5: Solve for x
    x = 635,978.34/688.80
  6. Step 6: Final answer
    x = 923.31

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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.