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Finding the Fourth Proportional to 890.19, 1,335.35 and 428.16

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Solution

The fourth proportional to 890.19, 1,335.35 and 428.16 is: 642.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.19 : 1,335.35 = 428.16 : x
  2. Step 2: Convert to fraction form
    890.19/1,335.35 = 428.16/x
  3. Step 3: Cross multiply
    890.19x = 1,335.35 × 428.16
  4. Step 4: Simplify right side
    890.19x = 571,743.46
  5. Step 5: Solve for x
    x = 571,743.46/890.19
  6. Step 6: Final answer
    x = 642.27

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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.