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Finding the Fourth Proportional to 489.65, 674.61 and 378.74

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Solution

The fourth proportional to 489.65, 674.61 and 378.74 is: 521.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.65 : 674.61 = 378.74 : x
  2. Step 2: Convert to fraction form
    489.65/674.61 = 378.74/x
  3. Step 3: Cross multiply
    489.65x = 674.61 × 378.74
  4. Step 4: Simplify right side
    489.65x = 255,501.79
  5. Step 5: Solve for x
    x = 255,501.79/489.65
  6. Step 6: Final answer
    x = 521.80

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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.