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Finding the Fourth Proportional to 1,137.80, 1,570.07 and 640.40

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Solution

The fourth proportional to 1,137.80, 1,570.07 and 640.40 is: 883.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,137.80 : 1,570.07 = 640.40 : x
  2. Step 2: Convert to fraction form
    1,137.80/1,570.07 = 640.40/x
  3. Step 3: Cross multiply
    1,137.80x = 1,570.07 × 640.40
  4. Step 4: Simplify right side
    1,137.80x = 1,005,466.58
  5. Step 5: Solve for x
    x = 1,005,466.58/1,137.80
  6. Step 6: Final answer
    x = 883.69

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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.