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Finding the Fourth Proportional to 890.21, 1,335.71 and 478.87

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Solution

The fourth proportional to 890.21, 1,335.71 and 478.87 is: 718.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.21 : 1,335.71 = 478.87 : x
  2. Step 2: Convert to fraction form
    890.21/1,335.71 = 478.87/x
  3. Step 3: Cross multiply
    890.21x = 1,335.71 × 478.87
  4. Step 4: Simplify right side
    890.21x = 639,629.31
  5. Step 5: Solve for x
    x = 639,629.31/890.21
  6. Step 6: Final answer
    x = 718.51

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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.