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Finding the Fourth Proportional to 715.91, 988.47 and 494.78

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Solution

The fourth proportional to 715.91, 988.47 and 494.78 is: 683.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    715.91 : 988.47 = 494.78 : x
  2. Step 2: Convert to fraction form
    715.91/988.47 = 494.78/x
  3. Step 3: Cross multiply
    715.91x = 988.47 × 494.78
  4. Step 4: Simplify right side
    715.91x = 489,070.24
  5. Step 5: Solve for x
    x = 489,070.24/715.91
  6. Step 6: Final answer
    x = 683.15

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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.