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Finding the Fourth Proportional to 891.30, 1,335.78 and 458.40

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Solution

The fourth proportional to 891.30, 1,335.78 and 458.40 is: 687.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.30 : 1,335.78 = 458.40 : x
  2. Step 2: Convert to fraction form
    891.30/1,335.78 = 458.40/x
  3. Step 3: Cross multiply
    891.30x = 1,335.78 × 458.40
  4. Step 4: Simplify right side
    891.30x = 612,321.55
  5. Step 5: Solve for x
    x = 612,321.55/891.30
  6. Step 6: Final answer
    x = 687.00

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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.