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Finding the Fourth Proportional to 781.84, 1,078.80 and 487.36

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Solution

The fourth proportional to 781.84, 1,078.80 and 487.36 is: 672.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.84 : 1,078.80 = 487.36 : x
  2. Step 2: Convert to fraction form
    781.84/1,078.80 = 487.36/x
  3. Step 3: Cross multiply
    781.84x = 1,078.80 × 487.36
  4. Step 4: Simplify right side
    781.84x = 525,763.97
  5. Step 5: Solve for x
    x = 525,763.97/781.84
  6. Step 6: Final answer
    x = 672.47

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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.