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Finding the Fourth Proportional to 487.78, 673.32 and 291.40

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Solution

The fourth proportional to 487.78, 673.32 and 291.40 is: 402.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.78 : 673.32 = 291.40 : x
  2. Step 2: Convert to fraction form
    487.78/673.32 = 291.40/x
  3. Step 3: Cross multiply
    487.78x = 673.32 × 291.40
  4. Step 4: Simplify right side
    487.78x = 196,205.45
  5. Step 5: Solve for x
    x = 196,205.45/487.78
  6. Step 6: Final answer
    x = 402.24

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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.