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Finding the Fourth Proportional to 768.96, 1,061.55 and 489.51

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Solution

The fourth proportional to 768.96, 1,061.55 and 489.51 is: 675.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.96 : 1,061.55 = 489.51 : x
  2. Step 2: Convert to fraction form
    768.96/1,061.55 = 489.51/x
  3. Step 3: Cross multiply
    768.96x = 1,061.55 × 489.51
  4. Step 4: Simplify right side
    768.96x = 519,639.34
  5. Step 5: Solve for x
    x = 519,639.34/768.96
  6. Step 6: Final answer
    x = 675.77

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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.