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Finding the Fourth Proportional to 630.17, 870 and 455.21

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Solution

The fourth proportional to 630.17, 870 and 455.21 is: 628.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    630.17 : 870 = 455.21 : x
  2. Step 2: Convert to fraction form
    630.17/870 = 455.21/x
  3. Step 3: Cross multiply
    630.17x = 870 × 455.21
  4. Step 4: Simplify right side
    630.17x = 396,032.70
  5. Step 5: Solve for x
    x = 396,032.70/630.17
  6. Step 6: Final answer
    x = 628.45

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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.