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Finding the Fourth Proportional to 1,137.50, 1,569.72 and 640.20

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Solution

The fourth proportional to 1,137.50, 1,569.72 and 640.20 is: 883.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,137.50 : 1,569.72 = 640.20 : x
  2. Step 2: Convert to fraction form
    1,137.50/1,569.72 = 640.20/x
  3. Step 3: Cross multiply
    1,137.50x = 1,569.72 × 640.20
  4. Step 4: Simplify right side
    1,137.50x = 1,004,934.74
  5. Step 5: Solve for x
    x = 1,004,934.74/1,137.50
  6. Step 6: Final answer
    x = 883.46

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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.