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Finding the Fourth Proportional to 809.78, 1,117.53 and 478.22

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Solution

The fourth proportional to 809.78, 1,117.53 and 478.22 is: 659.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.78 : 1,117.53 = 478.22 : x
  2. Step 2: Convert to fraction form
    809.78/1,117.53 = 478.22/x
  3. Step 3: Cross multiply
    809.78x = 1,117.53 × 478.22
  4. Step 4: Simplify right side
    809.78x = 534,419.61
  5. Step 5: Solve for x
    x = 534,419.61/809.78
  6. Step 6: Final answer
    x = 659.96

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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.