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Finding the Fourth Proportional to 628.74, 869.85 and 585

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Solution

The fourth proportional to 628.74, 869.85 and 585 is: 809.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.74 : 869.85 = 585 : x
  2. Step 2: Convert to fraction form
    628.74/869.85 = 585/x
  3. Step 3: Cross multiply
    628.74x = 869.85 × 585
  4. Step 4: Simplify right side
    628.74x = 508,862.25
  5. Step 5: Solve for x
    x = 508,862.25/628.74
  6. Step 6: Final answer
    x = 809.34

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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.