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Finding the Fourth Proportional to 916.81, 1,373.84 and 640.09

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Solution

The fourth proportional to 916.81, 1,373.84 and 640.09 is: 959.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    916.81 : 1,373.84 = 640.09 : x
  2. Step 2: Convert to fraction form
    916.81/1,373.84 = 640.09/x
  3. Step 3: Cross multiply
    916.81x = 1,373.84 × 640.09
  4. Step 4: Simplify right side
    916.81x = 879,382.16
  5. Step 5: Solve for x
    x = 879,382.16/916.81
  6. Step 6: Final answer
    x = 959.18

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.