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Finding the Fourth Proportional to 653.15, 987.13 and 641.81

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Solution

The fourth proportional to 653.15, 987.13 and 641.81 is: 969.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    653.15 : 987.13 = 641.81 : x
  2. Step 2: Convert to fraction form
    653.15/987.13 = 641.81/x
  3. Step 3: Cross multiply
    653.15x = 987.13 × 641.81
  4. Step 4: Simplify right side
    653.15x = 633,549.91
  5. Step 5: Solve for x
    x = 633,549.91/653.15
  6. Step 6: Final answer
    x = 969.99

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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.