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Finding the Fourth Proportional to 890.20, 1,228.47 and 497.21

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Solution

The fourth proportional to 890.20, 1,228.47 and 497.21 is: 686.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.20 : 1,228.47 = 497.21 : x
  2. Step 2: Convert to fraction form
    890.20/1,228.47 = 497.21/x
  3. Step 3: Cross multiply
    890.20x = 1,228.47 × 497.21
  4. Step 4: Simplify right side
    890.20x = 610,807.57
  5. Step 5: Solve for x
    x = 610,807.57/890.20
  6. Step 6: Final answer
    x = 686.15

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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.