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Finding the Fourth Proportional to 817.20, 1,126.44 and 642.32

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Solution

The fourth proportional to 817.20, 1,126.44 and 642.32 is: 885.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.20 : 1,126.44 = 642.32 : x
  2. Step 2: Convert to fraction form
    817.20/1,126.44 = 642.32/x
  3. Step 3: Cross multiply
    817.20x = 1,126.44 × 642.32
  4. Step 4: Simplify right side
    817.20x = 723,534.94
  5. Step 5: Solve for x
    x = 723,534.94/817.20
  6. Step 6: Final answer
    x = 885.38

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Double scale
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1.5x scale

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.