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Finding the Fourth Proportional to 718.46, 990.69 and 485.18

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Solution

The fourth proportional to 718.46, 990.69 and 485.18 is: 669.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.46 : 990.69 = 485.18 : x
  2. Step 2: Convert to fraction form
    718.46/990.69 = 485.18/x
  3. Step 3: Cross multiply
    718.46x = 990.69 × 485.18
  4. Step 4: Simplify right side
    718.46x = 480,662.97
  5. Step 5: Solve for x
    x = 480,662.97/718.46
  6. Step 6: Final answer
    x = 669.02

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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.