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Finding the Fourth Proportional to 487.78, 672.93 and 291.25

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Solution

The fourth proportional to 487.78, 672.93 and 291.25 is: 401.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.78 : 672.93 = 291.25 : x
  2. Step 2: Convert to fraction form
    487.78/672.93 = 291.25/x
  3. Step 3: Cross multiply
    487.78x = 672.93 × 291.25
  4. Step 4: Simplify right side
    487.78x = 195,990.86
  5. Step 5: Solve for x
    x = 195,990.86/487.78
  6. Step 6: Final answer
    x = 401.80

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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.