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Finding the Fourth Proportional to 1,386.92, 2,081.28 and 656.57

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Solution

The fourth proportional to 1,386.92, 2,081.28 and 656.57 is: 985.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,386.92 : 2,081.28 = 656.57 : x
  2. Step 2: Convert to fraction form
    1,386.92/2,081.28 = 656.57/x
  3. Step 3: Cross multiply
    1,386.92x = 2,081.28 × 656.57
  4. Step 4: Simplify right side
    1,386.92x = 1,366,495.60
  5. Step 5: Solve for x
    x = 1,366,495.60/1,386.92
  6. Step 6: Final answer
    x = 985.28

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1.5x scale

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.