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Finding the Fourth Proportional to 890.02, 1,228.21 and 491.68

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Solution

The fourth proportional to 890.02, 1,228.21 and 491.68 is: 678.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.02 : 1,228.21 = 491.68 : x
  2. Step 2: Convert to fraction form
    890.02/1,228.21 = 491.68/x
  3. Step 3: Cross multiply
    890.02x = 1,228.21 × 491.68
  4. Step 4: Simplify right side
    890.02x = 603,886.29
  5. Step 5: Solve for x
    x = 603,886.29/890.02
  6. Step 6: Final answer
    x = 678.51

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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.