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Finding the Fourth Proportional to 656.64, 989.94 and 621.36

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Solution

The fourth proportional to 656.64, 989.94 and 621.36 is: 936.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.64 : 989.94 = 621.36 : x
  2. Step 2: Convert to fraction form
    656.64/989.94 = 621.36/x
  3. Step 3: Cross multiply
    656.64x = 989.94 × 621.36
  4. Step 4: Simplify right side
    656.64x = 615,109.12
  5. Step 5: Solve for x
    x = 615,109.12/656.64
  6. Step 6: Final answer
    x = 936.75

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.