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Finding the Fourth Proportional to 647.12, 970.68 and 214.40

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Solution

The fourth proportional to 647.12, 970.68 and 214.40 is: 321.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.12 : 970.68 = 214.40 : x
  2. Step 2: Convert to fraction form
    647.12/970.68 = 214.40/x
  3. Step 3: Cross multiply
    647.12x = 970.68 × 214.40
  4. Step 4: Simplify right side
    647.12x = 208,113.79
  5. Step 5: Solve for x
    x = 208,113.79/647.12
  6. Step 6: Final answer
    x = 321.60

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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.