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Finding the Fourth Proportional to 891.90, 1,338.70 and 429.99

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Solution

The fourth proportional to 891.90, 1,338.70 and 429.99 is: 645.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.90 : 1,338.70 = 429.99 : x
  2. Step 2: Convert to fraction form
    891.90/1,338.70 = 429.99/x
  3. Step 3: Cross multiply
    891.90x = 1,338.70 × 429.99
  4. Step 4: Simplify right side
    891.90x = 575,627.61
  5. Step 5: Solve for x
    x = 575,627.61/891.90
  6. Step 6: Final answer
    x = 645.39

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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.