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Finding the Fourth Proportional to 809.76, 1,117.50 and 478.38

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Solution

The fourth proportional to 809.76, 1,117.50 and 478.38 is: 660.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.76 : 1,117.50 = 478.38 : x
  2. Step 2: Convert to fraction form
    809.76/1,117.50 = 478.38/x
  3. Step 3: Cross multiply
    809.76x = 1,117.50 × 478.38
  4. Step 4: Simplify right side
    809.76x = 534,589.65
  5. Step 5: Solve for x
    x = 534,589.65/809.76
  6. Step 6: Final answer
    x = 660.18

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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.