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Finding the Fourth Proportional to 890.60, 1,228.30 and 558.40

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Solution

The fourth proportional to 890.60, 1,228.30 and 558.40 is: 770.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.60 : 1,228.30 = 558.40 : x
  2. Step 2: Convert to fraction form
    890.60/1,228.30 = 558.40/x
  3. Step 3: Cross multiply
    890.60x = 1,228.30 × 558.40
  4. Step 4: Simplify right side
    890.60x = 685,882.72
  5. Step 5: Solve for x
    x = 685,882.72/890.60
  6. Step 6: Final answer
    x = 770.14

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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.