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Finding the Fourth Proportional to 1,640, 2,457 and 1,289.36

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Solution

The fourth proportional to 1,640, 2,457 and 1,289.36 is: 1,931.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,640 : 2,457 = 1,289.36 : x
  2. Step 2: Convert to fraction form
    1,640/2,457 = 1,289.36/x
  3. Step 3: Cross multiply
    1,640x = 2,457 × 1,289.36
  4. Step 4: Simplify right side
    1,640x = 3,167,957.52
  5. Step 5: Solve for x
    x = 3,167,957.52/1,640
  6. Step 6: Final answer
    x = 1,931.68

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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.