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Finding the Fourth Proportional to 662.40, 987.84 and 655.20

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Solution

The fourth proportional to 662.40, 987.84 and 655.20 is: 977.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    662.40 : 987.84 = 655.20 : x
  2. Step 2: Convert to fraction form
    662.40/987.84 = 655.20/x
  3. Step 3: Cross multiply
    662.40x = 987.84 × 655.20
  4. Step 4: Simplify right side
    662.40x = 647,232.77
  5. Step 5: Solve for x
    x = 647,232.77/662.40
  6. Step 6: Final answer
    x = 977.10

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.