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Finding the Fourth Proportional to 1,370.81, 2,056.89 and 640.91

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Solution

The fourth proportional to 1,370.81, 2,056.89 and 640.91 is: 961.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,370.81 : 2,056.89 = 640.91 : x
  2. Step 2: Convert to fraction form
    1,370.81/2,056.89 = 640.91/x
  3. Step 3: Cross multiply
    1,370.81x = 2,056.89 × 640.91
  4. Step 4: Simplify right side
    1,370.81x = 1,318,281.37
  5. Step 5: Solve for x
    x = 1,318,281.37/1,370.81
  6. Step 6: Final answer
    x = 961.68

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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.