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Finding the Fourth Proportional to 890.30, 1,228.55 and 491.96

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Solution

The fourth proportional to 890.30, 1,228.55 and 491.96 is: 678.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.30 : 1,228.55 = 491.96 : x
  2. Step 2: Convert to fraction form
    890.30/1,228.55 = 491.96/x
  3. Step 3: Cross multiply
    890.30x = 1,228.55 × 491.96
  4. Step 4: Simplify right side
    890.30x = 604,395.62
  5. Step 5: Solve for x
    x = 604,395.62/890.30
  6. Step 6: Final answer
    x = 678.87

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1.5x scale

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.