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Finding the Fourth Proportional to 647.35, 971.15 and 257.28

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Solution

The fourth proportional to 647.35, 971.15 and 257.28 is: 385.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.35 : 971.15 = 257.28 : x
  2. Step 2: Convert to fraction form
    647.35/971.15 = 257.28/x
  3. Step 3: Cross multiply
    647.35x = 971.15 × 257.28
  4. Step 4: Simplify right side
    647.35x = 249,852.62
  5. Step 5: Solve for x
    x = 249,852.62/647.35
  6. Step 6: Final answer
    x = 385.96

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.