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Finding the Fourth Proportional to 781.73, 1,078.68 and 664.18

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Solution

The fourth proportional to 781.73, 1,078.68 and 664.18 is: 916.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.73 : 1,078.68 = 664.18 : x
  2. Step 2: Convert to fraction form
    781.73/1,078.68 = 664.18/x
  3. Step 3: Cross multiply
    781.73x = 1,078.68 × 664.18
  4. Step 4: Simplify right side
    781.73x = 716,434.99
  5. Step 5: Solve for x
    x = 716,434.99/781.73
  6. Step 6: Final answer
    x = 916.47

Related Problems

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Half scale
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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.