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Finding the Fourth Proportional to 784.29, 1,081.79 and 489.45

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Solution

The fourth proportional to 784.29, 1,081.79 and 489.45 is: 675.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    784.29 : 1,081.79 = 489.45 : x
  2. Step 2: Convert to fraction form
    784.29/1,081.79 = 489.45/x
  3. Step 3: Cross multiply
    784.29x = 1,081.79 × 489.45
  4. Step 4: Simplify right side
    784.29x = 529,479.67
  5. Step 5: Solve for x
    x = 529,479.67/784.29
  6. Step 6: Final answer
    x = 675.11

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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.