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Finding the Fourth Proportional to 642.81, 887.99 and 511.65

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Solution

The fourth proportional to 642.81, 887.99 and 511.65 is: 706.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.81 : 887.99 = 511.65 : x
  2. Step 2: Convert to fraction form
    642.81/887.99 = 511.65/x
  3. Step 3: Cross multiply
    642.81x = 887.99 × 511.65
  4. Step 4: Simplify right side
    642.81x = 454,337.53
  5. Step 5: Solve for x
    x = 454,337.53/642.81
  6. Step 6: Final answer
    x = 706.80

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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.