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Finding the Fourth Proportional to 312.88, 429.40 and 283.72

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Solution

The fourth proportional to 312.88, 429.40 and 283.72 is: 389.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.88 : 429.40 = 283.72 : x
  2. Step 2: Convert to fraction form
    312.88/429.40 = 283.72/x
  3. Step 3: Cross multiply
    312.88x = 429.40 × 283.72
  4. Step 4: Simplify right side
    312.88x = 121,829.37
  5. Step 5: Solve for x
    x = 121,829.37/312.88
  6. Step 6: Final answer
    x = 389.38

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.