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Finding the Fourth Proportional to 718.18, 990.91 and 423.40

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Solution

The fourth proportional to 718.18, 990.91 and 423.40 is: 584.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.18 : 990.91 = 423.40 : x
  2. Step 2: Convert to fraction form
    718.18/990.91 = 423.40/x
  3. Step 3: Cross multiply
    718.18x = 990.91 × 423.40
  4. Step 4: Simplify right side
    718.18x = 419,551.29
  5. Step 5: Solve for x
    x = 419,551.29/718.18
  6. Step 6: Final answer
    x = 584.19

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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.