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Finding the Fourth Proportional to 810.39, 1,118.48 and 478.79

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Solution

The fourth proportional to 810.39, 1,118.48 and 478.79 is: 660.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.39 : 1,118.48 = 478.79 : x
  2. Step 2: Convert to fraction form
    810.39/1,118.48 = 478.79/x
  3. Step 3: Cross multiply
    810.39x = 1,118.48 × 478.79
  4. Step 4: Simplify right side
    810.39x = 535,517.04
  5. Step 5: Solve for x
    x = 535,517.04/810.39
  6. Step 6: Final answer
    x = 660.81

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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.