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Finding the Fourth Proportional to 920.40, 1,268.64 and 723.12

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Solution

The fourth proportional to 920.40, 1,268.64 and 723.12 is: 996.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.40 : 1,268.64 = 723.12 : x
  2. Step 2: Convert to fraction form
    920.40/1,268.64 = 723.12/x
  3. Step 3: Cross multiply
    920.40x = 1,268.64 × 723.12
  4. Step 4: Simplify right side
    920.40x = 917,378.96
  5. Step 5: Solve for x
    x = 917,378.96/920.40
  6. Step 6: Final answer
    x = 996.72

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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.